Q&A - PSLE Math

[corneyAmber]

Michaelia0816:

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 ?


Just for checking,
Is the answer 357?

Yes, 357 chairs for the concert.

[Michaelia0816]

Thx

[Michaelia0816]

Thx ksi!

[Michaelia0816]

(2)Mrs Hoon made some cookies to sell. 3/4 of them were chocolate cookies and the rest were almond cookies. After selling 210 almond cookies and 5/6 of the chocolate cookies, she had 1/5 of the cookies left. How many cookies did Mrs Hoon sell?

[2DMommy]

Need help again,


1) Danny and Richard earned a total of $3850. Richard earned $1850 more than Danny. Danny earned $5 more than Richard each day and Richard worked 3 times as many days as Danny. How much did Richard earn each day ?

2) Tom bought some chocolates and gave half of them to John. John bought some swees and gave half of them to Tom. Tom ate 12 sweets and John ate 18 chocolates. After that, the number of sweets and chocolates Tom had were in the ratio 1:7 and the number of swees and chocolates John had were in the ratio 1:4. How many sweets did John buy ?

Thank you.

[dicoyote]

hi, am not able to identify the model to use for this question, thus seeking help, thanks in advanced


A shopkeeper had some blue and red pens in his book shop. There were twice as many red pens as blue pens. The shopkeeper sold the pens in bundles of 2 red pens and 3 blue pens. After selling all the blue pens, he still had 120 red pens left. How many pens did he have in his bookshop at first?

[the shadowed snake]

Michaelia0816:

(2)Mrs Hoon made some cookies to sell. 3/4 of them were chocolate cookies and the rest were almond cookies. After selling 210 almond cookies and 5/6 of the chocolate cookies, she had 1/5 of the cookies left. How many cookies did Mrs Hoon sell?

hi is the ans 252 or 960? :lol:

[Michaelia0816]

I think it is 960, due to my calculation

[Michaelia0816]

Thanks, the shadow snake, for your time to help to solve!

[charsen]

dicoyote:

hi, am not able to identify the model to use for this question, thus seeking help, thanks in advanced


A shopkeeper had some blue and red pens in his book shop. There were twice as many red pens as blue pens. The shopkeeper sold the pens in bundles of 2 red pens and 3 blue pens. After selling all the blue pens, he still had 120 red pens left. How many pens did he have in his bookshop at first?

Hi,
This Question is a two ratio problem and could be solved by cross multipication.
First,You subtract 120 from 2U.The 2U refers to the red pen at first.I am doing this so that the ratio of the pens at first is equal to the Selling ratio , which is 2:3.
If you cross multiply now,
(2U-120)x3=6U-360
6U-360=(2x1)u
4U=360
1U=360/4=90
no.of pens at first-3U-90x3=270(ans)
cheers