Monday, July 30, 2012

S7 Maths Supplement :) yummy!!

Maths supplement continues ...

S7:

In a school hall, chairs were arranged in rows such that there were exactly 9 chairs in each row. For a concert, Mr Ong brought 6 more chairs into the school hall and rearranged all the chairs. There are now exactly 7 chairs in each row and 12 more rows than before.

How many chairs are there in the school hall for the concert?

Have fun! :)
Mrs R
Posted by at

135 comments:

  1. NicholasTanJuly 30, 2012 at 12:25 AM

    i do not even understand one bit

    ReplyDelete
  2. AnonymousJuly 30, 2012 at 12:26 AM

    Arggh!

    ReplyDelete
    Replies
    1. UnknownJuly 30, 2012 at 1:45 AM

      Who are you

      Delete
    2. UnknownJuly 30, 2012 at 1:45 AM

      who r u

      Delete
    3. UnknownJuly 31, 2012 at 6:53 AM

      whoooooooooooooooooooooooooooooo are youuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu???????????????????????????????????

      Delete
    4. Evelyn SeeJuly 31, 2012 at 6:59 AM

      You don't have to care. It is obvious it is someone from our class...

      Delete
    5. UnknownJuly 31, 2012 at 7:10 AM

      I know that! Don't think I am stupid!

      Delete
    6. UnknownJuly 31, 2012 at 11:06 PM

      If u are not why u ask this stupid question

      Delete
    7. Nadine LeeAugust 1, 2012 at 5:22 AM

      What are you arguing about?

      Delete
    8. SabarnaAugust 7, 2012 at 5:16 AM

      This quarrel is time consuming. Let's just focus on this question.

      Delete
    9. Jia Xian :PAugust 17, 2012 at 3:48 AM

      Yup!T totally agree!

      Delete
    10. AnonymousOctober 12, 2012 at 6:56 AM

      And stop using the word 'stupid'

      Delete
  3. UnknownJuly 30, 2012 at 2:04 AM

    Is it 126?
    Chen Jing

    ReplyDelete
  4. nicholas tanJuly 30, 2012 at 2:31 AM

    i think it is 126

    ReplyDelete
  5. UnknownJuly 30, 2012 at 5:09 AM

    Total number of chairs is 357.

    ReplyDelete
  6. UnknownJuly 30, 2012 at 5:43 AM

    My answer is 357.

    ReplyDelete
  7. FlorenceJuly 30, 2012 at 5:45 AM

    My answer is 357 chairs.

    ReplyDelete
  8. Heng Wei KiatJuly 30, 2012 at 6:01 AM

    My answer is 357.

    ReplyDelete
    Replies
    1. SabarnaAugust 7, 2012 at 5:14 AM

      What method did you use? Is it the smileyface method?
      . .
      U

      Delete
  9. UnknownJuly 30, 2012 at 6:11 AM

    This comment has been removed by the author.

    ReplyDelete
  10. UnknownJuly 30, 2012 at 6:13 AM

    357 chairs.

    ReplyDelete
  11. jiayiJuly 30, 2012 at 6:44 AM

    it is 357 chairs

    ReplyDelete
  12. Darren MokJuly 30, 2012 at 6:50 AM

    I think is 357 chairs...i'm not so sure.

    ReplyDelete
  13. NadineJuly 30, 2012 at 6:52 AM

    I do not understand... that's why I haven't posted my answer...

    ReplyDelete
    Replies
    1. Evelyn SeeJuly 30, 2012 at 6:56 AM

      Me too... I: I do not really understand the question. :(

      Delete
    2. UnknownJuly 30, 2012 at 7:19 AM

      This comment has been removed by the author.

      Delete
    3. UnknownJuly 30, 2012 at 7:21 AM

      This comment has been removed by the author.

      Delete
    4. UnknownJuly 30, 2012 at 7:31 AM

      Total no. of chairs if arrange in 9:
      = (9xr) + 6
      Total no. of chairs if arrange in 7:
      = (7xr) + 84
      9r+6 = 7r+84
      9r-7r=84-6
      2r=78
      1r=39
      Total chairs= (9x39) +6
      = 357
      ( No. of Rows if arrange in 7 = 357 /7 = 51)

      Delete
    5. Nadine LeeJuly 31, 2012 at 1:24 AM

      I'm going to admit that I can't solve this. :-( Even Wei Xuan's explanation (which I appreciate) can't help me! I'm going to cry :(

      Delete
    6. UnknownJuly 31, 2012 at 3:21 AM

      I agree with Nadine. Wei Xuan's method is too complicated

      Delete
    7. Evelyn SeeJuly 31, 2012 at 6:18 AM

      Yeah... It is complicated... But I will try to work it out, I guess... Thanks! :)

      Delete
    8. Jia XianJuly 31, 2012 at 6:36 AM

      Wei Xuan,you are not supposed to write the working!!

      Delete
    9. Evelyn SeeJuly 31, 2012 at 6:45 AM

      Now I get Wei Xuan's explaination! ^_^
      Total no. of chairs if arrange in 9 chairs per row:
      = (9 x rows) + 6
      Total no. of chairs if arrange in 7 chairs per row:
      = (7 x rows) + 84(Why 84? Because 7 chairs x 12 more rows)
      9 rows + 6 = 7 rows + 84
      9 rows - 7 rows = 84 - 6
      2 rows = 78(84 - 6)
      1 rows = 39(78 / 2)
      Total chairs = (9 rows x 39) +6
      = 357 chairs
      ( No. of Rows if arrange in 7 ---> 357 chairs /7 chairs per row = 51 rows)
      I hope this explanation will help you understand what Wei Xuan was trying to say better! :3

      Delete
    10. UnknownJuly 31, 2012 at 6:49 AM

      FINALLY!

      Delete
    11. Evelyn SeeJuly 31, 2012 at 6:54 AM

      At first I also don't understand lol. Then my mother helped meh. :3

      Delete
    12. UnknownJuly 31, 2012 at 7:07 AM

      My method is algebra

      Delete
    13. UnknownJuly 31, 2012 at 11:06 PM

      me too!:)

      Delete
    14. RyanLauAugust 1, 2012 at 12:04 AM

      Wei xuan yr father help u right?

      Delete
    15. UnknownAugust 1, 2012 at 12:57 AM

      Ya. Just gave me some clues.

      Delete
    16. Tan Li XinAugust 3, 2012 at 5:11 AM

      Thanks Evelyn, ur explanation did help me.

      Delete
    17. Tan Li XinAugust 3, 2012 at 5:24 AM

      Why is 9 rows - 7 rows=84
      I don't understand!

      Delete
    18. Evelyn SeeAugust 4, 2012 at 12:33 AM

      No, it is 9 rows - 7 rows= 84-6 which is 2 rows = 78

      Delete
    19. Nadine LeeAugust 6, 2012 at 12:51 AM

      This comment has been removed by the author.

      Delete
    20. Nadine LeeAugust 6, 2012 at 1:02 AM

      Evelyn, where did you get the 9 rows and 7 rows? It's 9 CHAIRS and 7 CHAIRS, not rows. Now your explanation is not making sense.

      Delete
    21. Tan Li XinAugust 7, 2012 at 2:22 AM

      Why does 9 rows -7 rows=84-6?

      Delete
    22. SabarnaAugust 7, 2012 at 5:08 AM

      First, each row had 9 chairs. Now each row has 7 chairs. So, 2 chairs were taken from each row.
      All those 2 chairs from each row were joined together to form the 'extra 12 more rows' (as stated in the question)
      So now, the 12 rows of chairs, each having 7 chairs...
      12x7=84(There are 84 'extra' chairs.)

      The 84 chairs consists of...
      1. 2 chairs taken from each row previously.
      2. the extra 6 chairs that Mr Ong brought into the hall.

      84-6=78 (Note: 78 is the total no. of chairs taken from
      each row previously.)

      Do you understand this part? :D

      Delete
  14. PriscillaJuly 30, 2012 at 7:55 AM

    it is 357 chairs

    ReplyDelete
  15. AinulJuly 30, 2012 at 10:50 PM

    I think it is 357 chairs.

    ReplyDelete
  16. UnknownJuly 31, 2012 at 3:30 AM

    How did all of you get 357?
    Chen Jing

    ReplyDelete
  17. glenda hoJuly 31, 2012 at 5:00 AM

    I appreciate it that wei xuan is trying to help, but i too think that his method is too complicated to understand. Can someone help me?? I would really appreciate your help if you can just try to help me!:D

    ReplyDelete
  18. UnknownJuly 31, 2012 at 6:21 AM

    TNKS WEI XUAN!I UNDERSTAND YOUR METHOD.


    HEY GUYS, HOW COME YOU DON'T UNDERSTAND WEI XUAN'S METHOD?

    IT'S SO EASY AND TOO SIMPLE TO UNDERSTAND!

    ReplyDelete
    Replies
    1. UnknownJuly 31, 2012 at 11:11 PM

      you think it is simple but others think it is hard .U must understand others feeling

      Delete
    2. Ginwen~August 1, 2012 at 12:01 AM

      U're comment might hurt someone's feeling's u know, Nandan.

      Delete
    3. RyanLauAugust 1, 2012 at 12:06 AM

      Gin wen is right.

      Delete
    4. wh4tthefriesAugust 1, 2012 at 1:26 AM

      I agree with Gin Wen And can someone please help in a much more simpler way? Look at what I have posted and u can comment there! Thanks very much!

      Delete
    5. Dixon LowAugust 1, 2012 at 5:06 AM

      I agree with Gin Wen. Someone plz help me understand Wei Xuan's method.

      Delete
    6. Nadine LeeAugust 1, 2012 at 5:15 AM

      Don't type in full caps... it's like shouting. Please think from other people's point of view. May not be 'SO EASY' for them.

      Delete
    7. Evelyn SeeAugust 1, 2012 at 5:15 AM

      I think mine is pretty clear compared to Wei Xuan's... I dunno. Some may understand while some may not. Lol. And I agree with Gin Wen. You will HURT people's feelings instead of CHEERING them UP.

      Delete
    8. Nadine LeeAugust 1, 2012 at 5:53 AM

      Not. A type of encouragement.

      Delete
    9. UnknownAugust 2, 2012 at 1:01 AM

      Gin Wen is totally and completely correct and you are hurting those classmates who does not understand. Plus,you don't even know the answer at first only till Wei Xuan posted his working! SO DON'T BE A SMART ALEX!!!!!!!!!!!!

      Delete
    10. GlendaAugust 2, 2012 at 4:01 AM

      By typing that, you are indirectly saying that we r not smart,pardon me for saying this but dumb. The worst part is that it's in caps lock.... I mean, you are not the only smart person in class, you have your weaknesses and we have ours! Nobody's perfect you know?!

      Delete
    11. Jia XianAugust 3, 2012 at 2:18 AM

      NANDAN,WHY MUST YOU "SHOUT" AT PEOPLE???It may hurt people's feeling as people may not think it is a piece of cake so stop it.Hey!You are actually saying us not smart at all and anyone knows that no one is perfect including you!!!You have weakness and good stuff but we also have weakness and good stuff so don't think we are not smart!!!!!!!

      Delete
    12. Ginwen~August 3, 2012 at 3:03 AM

      OH MAN! Did my comment just droven a bunch of classmates totally mad with Nandan? What I meant was that Nandan should shared his understanding about Weixuan's method more politly, not saying that he is bad! OH GREAT! Please don't use my comment as a accuse to make Nandan bad. Maybe it IS really easy just there's a trick or something and we didn't know and Nandan does not know why we don't know so just let begones be begones(might spell wrongly) and make PEACE! No more shouting or be ANGRY with Nandan for NO REASONS when u haven't FOUND OUT THE TRUTH YET! OK? ( please say "ok!"! :)......)

      Delete
    13. Ginwen~August 3, 2012 at 3:26 AM

      And 1 more thing! Those who are ANGRY with Nandan and had posted your post, u might NOT REALIZED that u are CYBERBULLING by saying BAD things that makes Nandan sad and he might feel bad about himself just because U're guys DON'T EVEN KNOW HOW HE FEELS and the TRUTH. U guys had totally FORGOTTEN abut the INTERNET RULES, DIDN'T U GUYS? So I adviced u stopped it and apologised to Nandan about it. That way, we will be happy again. Right? :)

      Delete
    14. Ginwen~August 3, 2012 at 3:32 AM

      Next time I will NEVER EVER comment again except for those questions Mrs R. post and sharing my working in case this happens again! I wouldn't want to cause this silly commotion and hurting other's feelings. It is bad. :(

      Delete
    15. Evelyn SeeAugust 4, 2012 at 12:45 AM

      Sorry if it bothers you. I just hope Nandan won't be so rush again. xD

      Delete
    16. Mrs RAugust 6, 2012 at 1:53 AM

      Nandan what happen to showing STAR values.
      Mrs R

      Delete
    17. Glenda HoAugust 7, 2012 at 5:38 AM

      Nandan, if my comment hurt your feelings, please do not be saddened by it. I meant that nobody's perfect and that you should not do such things.
      REALLY SORRY if I hurt your feelings. I did not mean to

      Delete
    18. Jia Xian :)August 17, 2012 at 2:53 AM

      Oh...Nandan,if my comments hurt you please accept my "apologe".

      Delete
  19. Jia XianJuly 31, 2012 at 6:40 AM

    Help!I need someone's help!I cannot work it out and even understand a bit.Even Wei Xuan's working are still difficult to understand so I NEED SOMEONE'S HELP!!!! :(

    ReplyDelete
    Replies
    1. Evelyn SeeJuly 31, 2012 at 6:47 AM

      See my further explaination of what Wei Xuan was trying to say! I hope it helped you! :D

      Delete
    2. Jia XianJuly 31, 2012 at 11:05 PM

      This question must be a P6 question that is why this must use alegbra.

      Delete
    3. wh4tthefriesAugust 1, 2012 at 1:28 AM

      Evelyn, what i dont understand is why u add 6 in the first step!

      Delete
    4. Evelyn SeeAugust 1, 2012 at 5:01 AM

      6 is because of the 6 more chairs added. :)

      Delete
    5. SabarnaAugust 7, 2012 at 5:11 AM

      I used the 'smileyface' method. My answer is 357. We could also use number statements.

      Delete
  20. Jia XianJuly 31, 2012 at 6:44 AM

    I only know that 12x7=84 the working is needed.

    ReplyDelete
  21. UnknownJuly 31, 2012 at 7:00 AM

    SAME ANS!

    ReplyDelete
  22. UnknownJuly 31, 2012 at 10:55 PM

    This comment has been removed by the author.

    ReplyDelete
    Replies
    1. UnknownJuly 31, 2012 at 11:12 PM

      sooooooooooooooooooooooooooooooooo looooooooooooooooooooooong

      Delete
    2. Ginwen~July 31, 2012 at 11:55 PM

      My answer is 357 chairs but your method weixuan, is so !?! Can't understand!

      Delete
    3. UnknownAugust 1, 2012 at 12:26 AM

      This comment has been removed by the author.

      Delete
    4. UnknownAugust 1, 2012 at 4:09 AM

      Ginwen, please share your method and we can learn from you!

      Delete
    5. Ginwen~August 3, 2012 at 2:47 AM

      My's about the same as Thomas

      Delete
  23. UnknownJuly 31, 2012 at 11:40 PM

    This comment has been removed by the author.

    ReplyDelete
  24. UnknownJuly 31, 2012 at 11:43 PM

    hey guys I found the ans with another set of step.6 step only

    ReplyDelete
    Replies
    1. Ginwen~July 31, 2012 at 11:56 PM

      what method?

      Delete
    2. UnknownAugust 1, 2012 at 12:30 AM

      This comment has been removed by the author.

      Delete
    3. UnknownAugust 1, 2012 at 12:33 AM

      This comment has been removed by the author.

      Delete
    4. UnknownAugust 1, 2012 at 12:36 AM

      This comment has been removed by the author.

      Delete
    5. UnknownAugust 1, 2012 at 3:44 AM

      This comment has been removed by the author.

      Delete
  25. UnknownAugust 1, 2012 at 12:53 AM

    This comment has been removed by the author.

    ReplyDelete
  26. UnknownAugust 1, 2012 at 12:58 AM

    This comment has been removed by the author.

    ReplyDelete
  27. wh4tthefriesAugust 1, 2012 at 1:29 AM

    I have no clue what u r talking about! Someone pls help in a much more simpler way!!!

    ReplyDelete
    Replies
    1. UnknownAugust 1, 2012 at 1:49 AM

      Look at wei xuan's explanation.It's pretty clear.

      Delete
  28. RyanLauAugust 1, 2012 at 1:36 AM

    I have 357 chairs.

    ReplyDelete
  29. UnknownAugust 1, 2012 at 1:46 AM

    In a school hall, chairs were arranged in rows such that there were exactly 9 chairs in each row. For a concert, Mr Ong brought 6 more chairs into the school hall and rearranged all the chairs. There are now exactly 7 chairs in each row and 12 more rows than before.

    How many chairs are there in the school hall for the concert?

    9x+6=7x+(12*7)
    9x+6=7x+84
    9x-7x=84-6
    2x=78
    1x=39
    39*9=351
    351+6=357
    ans:357

    ReplyDelete
    Replies
    1. UnknownAugust 2, 2012 at 1:05 AM

      yours is easier than Wei Xuan's but still complicated!

      Delete
    2. GlendaAugust 2, 2012 at 4:05 AM

      I don't really understand the 2x=78 part.... But ur working helps me understand better.
      Thank u very much!

      Delete
    3. Ginwen~August 3, 2012 at 2:46 AM

      I understand yours as I use the same method as yours.

      Delete
    4. Ginwen~August 3, 2012 at 2:49 AM

      almost the same, not 100% same.

      Delete
    5. Tan Li XinAugust 3, 2012 at 5:08 AM

      Wow this is so complicated!

      Delete
  30. Tiew Wei XuanAugust 1, 2012 at 1:49 AM

    Hey guys,

    I thought Mrs R said to post your methods on here? I would like to learn more methods from you all

    ReplyDelete
    Replies
    1. Tan Li XinAugust 3, 2012 at 5:29 AM

      Ya, if u got 357 as ur answer,please share ur working

      Delete
  31. Madhu :DAugust 1, 2012 at 1:58 AM

    what is going on???
    can someone help us with simple to understand methods???
    I think my brain is going to burst from all that thinking for a long time!!!!!!!!!!!!!!


    ~madhu~

    ReplyDelete
    Replies
    1. SabarnaAugust 7, 2012 at 10:30 PM

      Can you understand my explanation? Why don't you say which part do you not understand. Is it the '12x7' part?
      . .
      U

      Delete
  32. This Awkward Turtle Loves MusicAugust 1, 2012 at 2:22 AM

    Pls help me i keep racking my brain for answers but no....pls help me!!!!

    ReplyDelete
    Replies
    1. AnonymousAugust 21, 2012 at 2:48 AM

      Sorry, but may I know who are you?

      Delete
  33. Nadine LeeAugust 1, 2012 at 5:21 AM

    I appreciate Evelyn and Wei Xuan trying to help but I am so confused. Can someone explain to me in person? Yes I know it's a bit demanding but I can't learn that well visually.

    ReplyDelete
    Replies
    1. Evelyn SeeAugust 1, 2012 at 5:33 AM

      This comment has been removed by the author.

      Delete
    2. Evelyn SeeAugust 1, 2012 at 5:40 AM

      I know. :) You are auditory so you can't understand well. I understand you. Maybe I will explain it to you tomorrow during class. :3

      Delete
    3. UnknownAugust 2, 2012 at 8:09 AM

      This comment has been removed by a blog administrator.

      Delete
    4. SabarnaAugust 7, 2012 at 4:50 AM

      Can you understand my working?
      Actually. Xue Yan's working is a bit simple. But it took time for me to understand some of the number statements.

      Delete
    5. Jia Xian :DAugust 17, 2012 at 3:51 AM

      Thanks for removing mine.I don't know how to remove it at all!

      Delete
  34. Nadine LeeAugust 1, 2012 at 5:41 AM

    This comment has been removed by the author.

    ReplyDelete
  35. UnknownAugust 1, 2012 at 11:10 PM

    How to do? Don't even understand. >:(

    ReplyDelete
    Replies
    1. GlendaAugust 2, 2012 at 4:09 AM

      advice: look at xue yuan's method its quite clear.

      Delete
    2. Evelyn SeeAugust 4, 2012 at 12:37 AM

      Yeah, Glenda is right. It's a bit clearer than Wei Xuan's. :)

      Delete
  36. wh4tthefriesAugust 2, 2012 at 5:37 AM

    Pls, someone, save me from all these thinking! I will need to pick your brains. ( whoever u are)

    ReplyDelete
  37. Jia XianAugust 3, 2012 at 10:15 PM

    My answer is 357 chairs.

    ReplyDelete
  38. SabarnaAugust 6, 2012 at 2:45 AM

    Finally, after looking at your comments and cracking my brains, I have solved the question. And I got the answer: 357
    I've typed my working down. I hope it helps.

    In a school hall, chairs were arranged in rows such that there were exactly 9 chairs in each row. There are now exactly 7 chairs in each row.
    So, 2 chairs were taken from each row.

    Now, there are 12 more rows than before.
    All those 2 chairs taken from each row are part of this extra 12 rows. And the 6 chairs added are also part of this 12 rows.

    Now, let's focus on the extra 12 rows. Each row has 7 chairs.
    So, 12x7=84
    There are 84 extra chairs.
    84-6=78
    78 is the addition of all the 2 chairs taken from each row as I mentioned earlier. 78/2=39
    There were 39 rows at first.

    So, to find the total no. of chairs,
    39x7=273
    12x7=84
    273+84=357

    or

    39x9=351
    351+6=357 (note: the 6 come from the '6 chairs added')

    Hope this helps and is clear to understand.
    Bye!

    ReplyDelete
    Replies
    1. K.AshwiniAugust 7, 2012 at 4:34 AM

      Thanks Sabarna!Now I finally understand how to do the question.

      Delete
    2. SabarnaAugust 7, 2012 at 4:55 AM

      I think my working is about the same as Evelyn's one.

      Delete
    3. Glenda HoAugust 7, 2012 at 5:48 AM

      THKS! really! Now I finally fully understand this question! really thank you sooooo very much!

      Delete
    4. wh4tthefriesAugust 8, 2012 at 1:34 AM

      OMG!!! Sabarna, you are a genius! II have to thank you so much! I really understand the question now! Thanks to you! Thank You! x100000000000000000

      Delete
  39. Tan Li XinAugust 7, 2012 at 2:31 AM

    Thanks!.Now I finally understand! I think this is like the smileyface method

    ReplyDelete
    Replies
    1. SabarnaAugust 7, 2012 at 4:47 AM

      Well actually, this is my method 1:number statements.
      I used the 'smileyface' method as my method 2 (Checking method).

      Delete
  40. wh4tthefriesAugust 8, 2012 at 1:36 AM

    According to Sarbana's steps, I finally understand and tried to clone a few more questions with different numbers. Well, I got stuck halfway and refered to her method again and tada! I got it!

    ReplyDelete

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