Percentage P6 2010 SA2 Maha Bodhi P2 Q16

Tom and Jerry shared a box of marbles. If Tom was given 10 fewer marbles, Jerry would have five times as many marbles as Tom. If Tom was given 10 more marbles, he would have ½ as many marbles as Jerry. What percentage of the marbles did Tom receive? [5 marks][Answer given: 25%]


T              J
- 10       + 10
---------------
  1     :      5
---------------
5 T - 50 --> J + 10
J --> 5 T - 60

T              J
+ 10       - 10
--------------
  1    :      2
--------------
2T + 20 --> J - 10
J --> 2 T + 30

5 T - 60 --> 2 T + 30
3 T --> 30 + 60 = 90
T --> 90/3 = 30

J --> 2 x 30 + 30 = 90

90 + 30 = 120

30/120 x 100% = 25%

Percentage P6 2010 SA2 Maha Bodhi P2 Q17

A group of 328 P5 children were divided into two teams at the P5 camp this year. There were 8 more children in Team B than in Team A. There were also 50% more boys in Team B than in Team A. If 3/8 of the girls were in Team B, (a) what percentage of the pupils in Team B are girls? (b) what percentage of the children are boys? Leave your answers as mixed numbers in the simplest form. [5 marks][Answers given: 28 and 4/7%, 60 and 40/41%]


328 + 8 = 336

336/2 = 168 -- Team B

328 - 168 = 160 -- Team A

A                             B
-----------------------------
B       G               B        G
---------            ------------
2                :         3
         5       :                   3
-----------------------------

2 B + 5 G --> 160

6 B + 15 G --> 3 x 160 = 480


3 B + 3 G --> 168

6 B + 6 G --> 2 x 168 = 336


9 G --> 480 - 336 = 144

3 G --> 3/9 x 144 = 48

48/168 x 100% = 28 4/7%

a) It was 28 4/7%.


3 B --> 168 - 48 = 120

5 B --> 5/3 x 120 = 200

200/328 x 100% = 60 40/41%

b) It was 60 40/41%.