Q&A - PSLE Math

[lee tong fong]

Hi, can anyone help me with another question


(6) A total of 84 girls and 231 boys wre involved in a CIP programmeto clean up a section of the beach.
(a) Find the greatest number of groups that can be formed so that all the boys and girls are distributed equally among all the groups.
(b) What is the the total number of children in each group?

Thanks you again

[PapayaDad]

lee tong fong:

Hi, can anyone help me in this question


1)The number of chickens in farm A and Farm B are in the ratio 9:1.
Farm A sold a certain number of chickens and Farm B sold 2/3 of its chickens.
As a result, both Farm A and Farm B each had 209 chickens left.

(a) How many chickens were sold by the 2 Farm in all?
(b) What percentage of farm A's chickens wre sold?

Thanks you

Farm B sold 2/3 ; so remaining 1/3 which is 209
So initially have 209 x 3 = 627
Sold is 209 x 2 = 418

So farm A initially have 627 x 9 = 5643
inthe end have 209
Sold is 5643 - 209 = 5434

Total sold is 418 + 5434 = 5852

[PapayaDad]

lee tong fong:

Hi, can anyone help me with another question


(6) A total of 84 girls and 231 boys wre involved in a CIP programmeto clean up a section of the beach.
(a) Find the greatest number of groups that can be formed so that all the boys and girls are distributed equally among all the groups.
(b) What is the the total number of children in each group?

Thanks you again

84/2 = 42
42/3 = 14
14/2 = 7

check 231/7 = 33

Answer :
7 groups
Each group have 84/7=12 girls ; and 231/7=33 boys
Each group have 12 + 33 = 45 children

[PapayaDad]

lee tong fong:

Hi, can anyone help me with another question


(3) To make a fruit cake, Mrs Lim used 90% strawberry and 10% mango.
The cost of the mangoes was 1.5 times that of the strawberries.
She spent $6.30 in all for the strawberries and mangoes
How much more would it cost her if she uses 40% strawbeey and 60% mango?

Thanks you again

The cost of the mangoes was 1.5 times that of the strawberries.
interms of cost
1m=1.5s
10m=15s
90s : 15s
6s:1s
7s = 630
s = 90
m = 135

4s=360
6m=810
total=1170

1170 - 630 = 540

[PapayaDad]

lee tong fong:

Hi, can anyone help me with another question


(4) Shaun and Chin Hong cycled along the same route from Point A to Point B
Shuan Cycled at the average speed of 20km/h and he was 4.5km ahead of Chin Hong when Chin Hong reached the half-way mark.
If Shuan reached Point B at 11:20am, what time would Chin Hong reach Point B?

Thanks you again

Shaun was 4.5km ahead of Chin Hong when Chin Hong reached the half-way mark.

So when Chin Hong reach Point B ; Shaun would have been 9km ahead (if he did not stop at point B and maintain the same average speed of 20km/h).

How long does it take Shaun to cover 9km? Answer 9/20 x 60 (minutes) = 27 minutes.

Chin Hong reach at 11.20 + 27 minutes = 11.47am

[Cecilia J]

Thanks.This was from my daughter’s school practice paper.

[MathIzzzFun]

lee tong fong:

Hi, can anyone help me with another question


(6) A total of 84 girls and 231 boys wre involved in a CIP programmeto clean up a section of the beach.
(a) Find the greatest number of groups that can be formed so that all the boys and girls are distributed equally among all the groups.
(b) What is the the total number of children in each group?

Thanks you again

Boys -> 231=21 x 11
Girls -> 84 = 21 x 4
maximum number of groups -> 21
Total number of chilgren in each group-> 11 + 4 = 15

cheers

[lee tong fong]

Thanks for your solutions.


For question 6, I would like to know how do you work out the maximum number of group is 21.

For question 3, is this possible to work out the solution using the (Number of units X Value of units)

[MathIzzzFun]

lee tong fong:

Thanks for your solutions.


For question 6, I would like to know how do you work out the maximum number of group is 21.

For question 3, is this possible to work out the solution using the (Number of units X Value of units)

Find the largest common factor of 84 and 231 which is 21.

cheers.

[S6169]

PapayaDad:

lee tong fong:

Hi, can anyone help me with another question


(3) To make a fruit cake, Mrs Lim used 90% strawberry and 10% mango.
The cost of the mangoes was 1.5 times that of the strawberries.
She spent $6.30 in all for the strawberries and mangoes
How much more would it cost her if she uses 40% strawbeey and 60% mango?

Thanks you again

The cost of the mangoes was 1.5 times that of the strawberries.
interms of cost
1m=1.5s
10m=15s
90s : 15s
6s:1s
7s = 630
s = 90
m = 135

4s=360
6m=810
total=1170

1170 - 630 = 540

Sorry, put S=90, m=135 back to the Q,
9s+m=90*9+135=945 not 630, something wrong?

if you use:
90s : 15s
105s=630
s=6
m=9
then 40s+60m=780
difference 780-630=150

:?