Q&A - P3 Math

[Muffins]

ChiefKiasu:

Here's another one, this time from Catholic High Primary 3 SA1:


Gregory and Timothy has 192 stickers together. After Timothy gave 30 stickers to Gregory, Timothy had thrice as many sticker as Gregory. How many stickers did Gregory have at first?

Again... no algebra please.

This is how I would do it:

G : T
1 3

4u is 192

1u is 48

48 - 30 = 18

[bwpj2000]

//Moderator's note: Topics merged.


Need help with these questions from my son's P4 homework:

Q1. Edward has $40 more than Fariq. If Edward gives 1/5 of his money to Fariq, Fariq will have 7/8 as much money as Edward. How much money do they have altogether?

Q2. When Janice bought some files, the average cost was $4. After she bought one more file at $16, the average cost was $7. How many files did she buy at first?

Q3. Alex's monthly salary is $80 more than Bernard's monthly salary. Every month, they spend $950 each and save the rest of their money. After a few months, Alex saved $2805 while Bernard saved $1605.
(a) How many months did Alex take to save $2805?
(b) What is the total amount of money Alex and Bernard will earn in a month?

Responses are very much appreciated.

[jedamum]

mods,

pls merge.
http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=149&start=0
TQ.

[tianzhu]

Hi

Q2 touches on averages.
Is averages covered in P4 Maths?

[bwpj2000]

I think averages is covered in P4 Math, I'm not very sure. :?

[Vanilla Cake]

bwpj2000:

Need help with these questions from my son's P4 homework:


Q1. Edward has $40 more than Fariq. If Edward gives 1/5 of his money to Fariq, Fariq will have 7/8 as much money as Edward. How much money do they have altogether?

Q2. When Janice bought some files, the average cost was $4. After she bought one more file at $16, the average cost was $7. How many files did she buy at first?

Q3. Alex's monthly salary is $80 more than Bernard's monthly salary. Every month, they spend $950 each and save the rest of their money. After a few months, Alex saved $2805 while Bernard saved $1605.
(a) How many months did Alex take to save $2805?
(b) What is the total amount of money Alex and Bernard will earn in a month?

Responses are very much appreciated.

Hi bwpj2000,
I don't think that these sums are for P4 level as they are most likely to be P5 Maths. Anyway, hope the below solutions help.

A1.
Edward -> unit + 40
Fariq -> unit

4/5 x (unit+40) = 4unit/5 + 32 = 0.8unit + 32
(0.8unit +32)/(1.2unit +8 ) = 8/7
8(1.2unit +8 ) = 7(0.8unit + 32)
9.6 unit + 64 = 5.6 unit + 224
4 units = 160
1 unit = 40

Total amount-> $(40x2) + 40 = $120

A2
16-7 = 9 (Extra from one more file)
7-4 = 3 (Increase in average ie each file increased by 3)

Number of files that Janice bought at first = 9/3 = 3

A3
(a) Number of months-> (2805-1605)/80 = 15

(b) Amount that Alex earned in 1 month = (2805/15)+950 = $1137
Total amount of money that Alex and Bernard earned in a month = $1137 + $(1137-80) = $2194

[elkniwt]

Hi,


I was going thr' this paper with my P3 girl. Need help in this qn. Thanks

Catholic High 2007 CA2 Q40.

http://www.postimage.org/image.php?v=Ts2ds4FJ

[watmekiasu]

I've deleted my answer since it is not right. Do not wish anyone to waste time figuring out my method. :lol:

[elkniwt]

watmekiasu:

Elkniwt


Hope this is correct -

1st - 3/8 + 3/8 = 6/8 = 3/4
2nd - 1/12 + 1/12 = 2/12 = 1/6
3rd - 1/3 + 1/6 = 3/6 = 1/3

so, the answer is 1/6

The ans given by the ans sheet is 2/9. I couldn't get it.

[qic]

The answer is as follows:


3/8-1/8+3/8/+1/8=6/8=3/4
4/12-1/3+1/12+1/12=2/12=1/6
3/9-1/3+?+1/9=1/3=3/9

?=2/9