Q&A - P5 Math

[Jerico]

Hi,

Can someone please advise how to solve this problem in more details as I unfortunately do not understand magicpiglet's solution ? Tks.

Q : Ali and Danny had a total of 108 stickers at first. In
the first game, Ali lost 0.25 of his stickers to Danny. In the second game, Danny lost 2/5 of his stickers to Ali. In the end, they had the same number of stickers left. How many more stickers did Danny have than Ali at first ?

Tks in advance for your help !

[Jerico]

Hi,

Will greatly appreciate if someone can please help to solve the attached question :-

Thank you very much !

[Jerico]

Hi,

Pls help to solve the attached.

Thank you in advance !

[tanxexy]

Hi,

Will greatly appreciate if someone can please help to solve the attached question :-

Thank you very much !

Hi Jerico,

2/9 of A = 2/7 of B
=> A = 9/2 x 2/7 of B = 9/7 of B
=> A = 9u and B = 7u; Shaded = 2u
=> Total area = 9u + 7u - 2u = 14u
(a) Therefore, the shaded area is 2/14 = 1/7 of the total area.

(b) 2u = 112 => 14u = 112 x 7 = 784 cm2

Hope that helps!

[tanxexy]

Hi,

Pls help to solve the attached.

Thank you in advance !

Hi Jerico,

Brand A: 4/10 => Brand B & C: 6/10

Brand B : Brand C = 1 : 3
=> Brand B: 1.5/10 = 3/20
and Brand C: 4.5/10 = 9/20

Expressing in same denominator, Brand A: 4/10 = 8/20

Let the total number of socks sold be 20u.
In terms of $,
Brand A: 8u x $10 = $80u
Brand B: 3u x $11 = $33u
Brand C: 9u x $12 = $108u

80u + 33u + 108u = 221u = 3978
=> u = 18

Brand C: $108 x 18 = $1944
Brand B: $33 x 18 = $594
Brand A: $80 x 18 = $1440
Difference = (1944+594) - 1440 = $1098

cheers!

[tanxexy]

Hi,

Can someone please advise how to solve this problem in more details as I unfortunately do not understand magicpiglet's solution ? Tks.

Q : Ali and Danny had a total of 108 stickers at first. In
the first game, Ali lost 0.25 of his stickers to Danny. In the second game, Danny lost 2/5 of his stickers to Ali. In the end, they had the same number of stickers left. How many more stickers did Danny have than Ali at first ?

Tks in advance for your help !

Hi Jerico,

We have to work this out backwards. Note the total number of stickers remained unchanged at 108 throughout.

(1) In the end, they had the same =>
108/2 = 54 => They both had 54 at the end.

(2) Before 2nd game
Danny had 54 stickers after he lost 2/5 of them to Ali
=> 54 = 3/5 of his stickers
=> he had (54 x 5/3) = 90 stickers before the 2nd game (which he lost to Ali).
=> Ali had 108 - 90 = 18 stickers before the 2nd game.

(3) Before 1st game
Ali was left with 18 stickers which was 0.75 or 3/4 of his stickers after he lost
=> Ali had (18 x 4/3) = 24 stickers before he lost to Danny in the 1st game
=> Danny had 108 - 24 = 84 stickers at first
=> Danny had 84 - 24 = 60 more stickers than Ali at first

Hope it is clearer to you now.

cheers!

[Prudence99]

Hi,

Here is a question which I also have the steps to solving the problem but I need clarification on one step. Kindly assist.

Mrs Lee made some cookies and packed them in 50 small boxes and 12 big boxes that had an equal number of cookies each. Each big box had 30 more cookies than each small box. 5/8 of the cookies made were packed in small boxes.
(a) Mrs Lee collected $559.90 after selling all the small boxes of cookies at $8.55 each and some big boxes of cookies at $16.50 each. How many big boxes of cookies were left?
(b) How many cookies did Mrs Lee make?

So the steps to solving (b) is as follows:

Big Small Total
3 5 8
(x10) 30 50 80

12 big boxes = 12u + (30x12)
30u = 12u + 360
18u = 360
1u = 20

Total cookies made = 80u x 20
= 1,600

Question: why do we multiply the original ratio by 10?

Many thanks in advance!

[tanxexy]

Hi,

Can someone please advise how to solve this problem in more details as I unfortunately do not understand magicpiglet's solution ? Tks.

Q : Ali and Danny had a total of 108 stickers at first. In
the first game, Ali lost 0.25 of his stickers to Danny. In the second game, Danny lost 2/5 of his stickers to Ali. In the end, they had the same number of stickers left. How many more stickers did Danny have than Ali at first ?

Tks in advance for your help !

Hi Jerico,

Here are the model diagrams I try to illustrate magicpiglet's solution:


Hope it is self explanatory.

[Jerico]

Thanks a million tanxexy for your great help ! You are a lifesaver !

[redruby]

Dennis bought a book. He read 3/5 of the book on the first day and 1/4 of the remaining book on the second day. If Dennis read 4 pages of the book on the second day, how many pages of the book are left unread?