Q&A - P5 Math

[Jamesbond]

dazzlego:

Jamesbond:

Three classes 4B, 4C& 4D donated some money to charity. The donation made by 4B was 1/3 as much as the total donation made by 4C and 4D. The donation made by 4C was 2/5 as much as the total donation made by 4B and 4D. If 4C donated $135 less than 4D, how much was collected from each class?

The ans is 4B-$189. 4C-$216. 4D-$351. Can somebody explain me how to derive it. Thx.

Hi Jamesbond,

B : C+D = 1:3 (Total: 4)
C : B+D = 2:5 (Total: 7)
Total is the same,
B : C+D = 7:21 (Total: 28)
C : B+D = 8:20 (Total: 28)

B -> 7 units
C -> 8 units
D -> 13 units

5 units -> $135
1 unit -> $27

4B: 7 untits -> $189
4C: 8 units -> $216
4D: 13 units -> $351

Cheers :celebrate:

Thx Dazzlego. My DS just entering P5. Since ratio is new to him he finds it difficult to follow the steps. Can u pl help using some other method.

[Jamesbond]

:thankyou:

[ahxuan.031873ymail.031873com]

Hi,


My child has misplaced it. Anyone can email me a copy? Many Thanks.

[concerned1970]

shawnlim88:

concerned1970:

4) Mr F had a sum of money. He gave half of his money plus $570 to his wife. He gave half of the remainder plus $420 to his parents. Then he gave half of the remainder to his daughter, Abby. He also bought a dress that cost $89 for Abby. If Mr F was left with $568, how much money did he have at first?

<------------------------------ WIFE --------------------------->
<---------------------------------------------------------->|570|
<------------------------>|420|<---------Parent------->|
<----------->|<--Abby->|
<568>|<89>
so:
<568>|<89>
|<--Abby-->|420|
<----Parent----->|
<---------------->|570|
<------WIFE ---------->

568 + 89(dress) = 657
abby gest 657
before giving abby: 657*2 = 1314

parents get: additional 420 = 1734
before giving parents: 1734*2= 3468

wife gets additional 570 : 4038
before giving wife: 4038*2 = 8076

answer: $8076

hope it helps.
i don't think a P5 student is able to solve this under exam condition.
:stupid: :stupid: :stupid:

Hi Shawn, my DS teacher did set this as exam ques, unfortunately he din get it right.

[jarenchuatw]

Need help in the following 2 questions:

1. To number the pages of a story book, 642 digits (0,1,2…9) are needed. How many pages does the story book have?
2. A total of 683 balls with 3 different colours, brown, green and white are arranged in the pattern of BBGGGWWWW. What is the colour of the last ball?

[vsk]

Hi everyone, i would like to seek your help in doing this question.


A watch and a pen cost $105. If 3 pens cost $27 more than the watch, find the cost of such 2 watches?

thks :thankyou:

[MathIzzzFun]

vsk:

Hi everyone, i would like to seek your help in doing this question.


A watch and a pen cost $105. If 3 pens cost $27 more than the watch, find the cost of such 2 watches?

thks :thankyou:

3 pens = 1 watch + $27

1 watch + 1 pen = $105
3 watches + 3 pens = $315
3 watches + (1 watch + $27) = $315
1 watch --> $72

cheers.

[vsk]

Thank you MathIzzzFun for the solution. It really helped. :thankyou:

[vsk]

Hi everyone. I need your help in solving this question.Thks.


The total cost of 9 forks and 5 knives cost $71. the total cost of 3 forks and 3 knives is $33. find the difference in cost between a fork and a knife.





:thankyou:

[AtoZ]

Hi there, I need your help!


In a library, the number of adults was 3/5 of the number of children at first. Then 6 adults and 4 children came in and the number of adults became 3/4 of the number of children. How many people were at the library at first?

Thank you!