Q&A - PSLE Math

[Emelyn]

Hi,


Need some urgent help here.

Qn : Jan and Kay had equal number of sweets and equal number of chocolates. Jan ate 12 sweets and Kay ate 18 chocolates and then the ratio of Jan’s sweets to chocolates became 1:7, and the ration of Kay’s sweets to chocolates became 1:4. How many sweets did Jan have at first ?

MTIA !!

[tianzhu]

Happy Mama:

Hi Tianzhu, the numbers are correct. We are also wondering why as we have tried and even tried backwards and it didn't work. Thanks so much.

Hi Happy Mama

Based on the original question, you’ll get the answer in decimals.

If you change 20% to 30%, you’ll get a nice numbers for the answer.

Best wishes

[tianzhu]

Emelyn:

Hi,


Need some urgent help here.

Qn : Jan and Kay had equal number of sweets and equal number of chocolates. Jan ate 12 sweets and Kay ate 18 chocolates and then the ratio of Jan's sweets to chocolates became 1:7, and the ration of Kay's sweets to chocolates became 1:4. How many sweets did Jan have at first ?

MTIA !!

Hi Emelyn

This question has been discussed earlier.

This question is a modified version of a question from PSLE 2009.

You may use MD or Units Method to solve it.

Once you get the MD done, all you need to do is to compare the number of chocolates of Jan and Kay.

Hope this helps.

Best wishes.

http://farm6.static.flickr.com/5133/5473929452_1688f4c2ee_b.jpg\">

[Happy Mama]

tianzhu:

Happy Mama:

Hi Tianzhu, the numbers are correct. We are also wondering why as we have tried and even tried backwards and it didn't work. Thanks so much.

Hi Happy Mama

Based on the original question, you’ll get the answer in decimals.

If you change 20% to 30%, you’ll get a nice numbers for the answer.

Best wishes

Oh ok. Thank you very much, Tianzhu.

[tianzhu]

Happy Mama:

Oh ok. Thank you very much, Tianzhu.

Hi Happy Mama

You're welcome.

Best wishes

[Emelyn]

tianzhu:

Emelyn:

Hi,


Need some urgent help here.

Qn : Jan and Kay had equal number of sweets and equal number of chocolates. Jan ate 12 sweets and Kay ate 18 chocolates and then the ratio of Jan's sweets to chocolates became 1:7, and the ration of Kay's sweets to chocolates became 1:4. How many sweets did Jan have at first ?

MTIA !!

Hi Emelyn

This question has been discussed earlier.

This question is a modified version of a question from PSLE 2009.

You may use MD or Units Method to solve it.

Once you get the MD done, all you need to do is to compare the number of chocolates of Jan and Kay.

Hope this helps.

Best wishes.

Oopss... sorry.... for not checking the earlier discussion.
Thanks for explaining it again.

[is_me_lblue]

Hi,


Is m again.

5 sharpeners and 8 books cost $ 49. If 1 sharpener and 1 book cost $u, Find the cost if 9 books.


Thank you.

[Belle2011]

is_me_lblue:

Hi,


Is m again.

5 sharpeners and 8 books cost $ 49. If 1 sharpener and 1 book cost $u, Find the cost if 9 books.

Thank you.

I can't think of any method except \"algebra\" method.

5s + 8b = 49
Since 1s + 1b = u, so 5s + 5b = 5u.
Subtracting:
3b = 49-5u
9 books = 9b = 3(49-5u).

[is_me_lblue]

Belle2011:

is_me_lblue:

Hi,


Is m again.

5 sharpeners and 8 books cost $ 49. If 1 sharpener and 1 book cost $u, Find the cost if 9 books.

Thank you.

I can't think of any method except \"algebra\" method.

5s + 8b = 49
Since 1s + 1b = u, so 5s + 5b = 5u.
Subtracting:
3b = 49-5u
9 books = 9b = 3(49-5u).

Thank you. Same as me but the answer sheet given is $(147-15u).I want to confirm is the answer sheet wrong or ?

[Belle2011]

is_me_lblue:

Thank you. Same as me but the answer sheet given is $(147-15u).I want to confirm is the answer sheet wrong or ?

147-15u = 3(49-5u) !!!