EP2 Percentage : Mathematics Word Problems Questions

PSLE questions (2007 to 2011)

1.  In a group of 80 children, 56 were girls. What percentage of the children were boys ? (Note : of the children -> denominator will be number of children)

Boys -> 80 – 56 = 24

24/80 = 6/20 = 30/100 =30%

2.  Shah, Raja and Mark shared $450. Raja received 20% more than Shah while Mark received 20% less than Shah. How much more than Mark did Raja receive ?

Draw Model

  

Shah -> 100%

Raja -> 100% + 20% = 120%

Mark -> 100% - 20% = 80%

Total percentage 100% + 120% + 80% = 300%

300% -> $450

10% -> $15

Mark -> 80% -> 8 x $15 = $120

Rajal -> 120% -> 12 x $15 = $180

Difference -> $180 - $120 = $60

3.  Hamid donated 20% of his savings and still had $180 of his savings left. How much money did he donate ?

80% -> $180

20% -> $45

4.  Express 7/20 as a percentage

7/20 = 35/100 = 35%

5.  Express 2.3 as a percentage.

Move to the 2 places to the right or multiply by 100% -> 2.4 x 100% = 240%

6.  Jenny paid $69 for an electric kettle after a discount of 40%.

What was the price of the kettle before the discount?

60% -> $69

10% -> $11.50

100% -> $115

7. Mr Wong had a number of books for sale. He sold a total of 342 books on Saturday and

Sunday. On Monday, he sold  of the remainder. He was left with 18% of the books he had at first. How many books did he have at first?

3u -> 18%

1u -> 6%

4u -> 24%

100% - 24%= 76%

76% -> 342

1%-> 4.5

100% -> 450

8.  Mrs Cheng bought a bag and a pair of shoes at a discount. She spent a total of $57.60 on these two items. She spent $9.60 more on the shoes than on the bag.

How much did she spend on the shoes ?

The total discount given for the two items was $22.40. She was given a 25% discount for the bag. What was the percentage discount given for the shoes?

(**Note : students normally confused on which one should be the denominator for the percentage, for this case is the original price)

2u + $9.60 = $57.60

2u = $57.60 - $9.60 = $48

u = $24

Shoes -> $24 + $9.60 = $33.60

Bag -> 75% -> $24

25% -> $8

Discount for the bag -> $8

Discount for the shoes -> $22.40 - $8 = $14.40

Original shoes price -> $33.60 + $14.40 = $48

Percentage discount -> 14.40/48 = 0.6/2 = 30/100 = 30% or 14.40/48 x 100% = 30%

9. At first, Lisa had a total of 66 blue and pink balloons. 17 pink balloons burst. She then increased the number of blue balloons by 75%. After that, Lisa had a total of 79 balloons.

** Draw model

How many pink balloons did she have at first?

Number of balloons left -> 66 – 17 = 49

Number of balloons increased -> 79 – 49 = 30

75% -> 30

25% -> 10

100% -> 40

Blue balloons -> 40

Pink balloons -> 66 – 40 = 26

PSLE (2012 to 2014)

10. The pie chart shows how a class of 40 pupils go to school. What percentage of the class walk to school ? (2012 Paper 1, 1 mark)

11.  A shop sells T-shirt in four different sizes. The table shows the number of T-shirts sold in June for size S, M and L but not XL. (2012, Paper 1, 2 marks)

Size of T-shirt	Number of T-shirts
S	140
M	302
L	95
XL

50% of the T-shirts sold were in size M. How many of the T-shirts sold were in size XL?

Total -> 302 x 2 = 604

XL -> 604 – 140 -302 – 95 = 67

12.  In July the number of T–shirts sold in size XL remained the same but there was an increase in the number of T-shirts sold in the other sizes. Did the percentage of the T-shirts sold in size XL increase, decrease or remain the same from June to July ?

When the total increase, XL remained -> fraction became smaller -> % decrease

13.  Participants of a quiz must obtain at least a certain score in the first round to qualify for the second round. There were 160 participants in the first round and the table shows the number of participants for each score.

Score	Number of participants
0	13
1	17
2	18
3	34
4	48
5 or more	30

30% of the participants did not qualify for the second round. From the table, what was the lowest score of a participant who qualified for the second round? (2012, Paper 1, 2 marks)

  30% of the participants -> 30% of 160 = 30/100 x 160 = 48

Count from lowest score and total up the number of participants, 48 is in score 2. -> Lowest score of a participant who qualified -> Score 3

14.  Lisa had a collection of stamps from Australia, France and Japan. She had 124 stamps from Australia. 30% of her stamps were from France. She had 12 fewer stamps from Japan than from France. (2012 Paper 2, 5 marks)

What was the total number of stamps in Lisa’s collection?

Lisa’s aunt gave her some stamps from France. Her total collection increased by 25%. What percentage of her collection was from France after that? (Note : of her collection after that -> denominator is total after the increase)

100% -> 280

25% -> 70

Total collection after increase -> 280 + 70 = 350

France -> 30% -> 28 x 3 = 84

France after increase -> 84 + 70 = 154

Percentage after increase ->  = =  =  = 44% or  x 100% = 44%

15.  The pie chart shows the favourite colours of a group of children.  What percentage of the children chose Blue as their favourite colour? (2013, Paper 1, 1 mark)

16.  Gerald was given a fixed amount of pocket money each month. In January he spent $50 and saved the rest. In February she spent 10% less and his savings increased by 25%. How much was Gerald’s pocket money for each month? (2013 Paper 2, 2 mark)

Spent -> 10% of $50 = $5

Savings ->     25% -> $5

100% -> $20

Total -> $50 + $20 = $70

17.  Mrs Wong bought a rice cooker for $126 after a discount of 30%.

What was the price of the rice cooker before discount?

70% -> $126

10% -> $18

100% -> $180

She paid $40 for a toaster. The total discount for the rice cooker and the toaster was $64. What was the percentage discount given for the toaster? (2013 Paper 2, 5mark)

Rice cooker discount -> $180 - $126 = $54

Toaster discount -> $64 - $54 = $10

Percentage of discount for toaster = 10/50 = 20/100 = 20%

18.  After a discount of 25%, the price of a concert ticket is $60. Senior citizens are given a further discount of $12. What is the total percentage discount given to senior citizens for the ticket? (2014, Paper 1, 1mark)

75% -> $60

25% -> $20

100% -> $80

Total discount -> $20 + $12 = $32

Total percentage discount -> 32.80 = 8/20 = 40/100 = 40% or 32/80 x 100% = 40%

19.  A youth club has 50 male and 70 female members. 16% of the male members and 10% of the female members are students. What percentage of the members are students ? (2014, Paper 2, 2 mark)

Male students -> 16% of 50 = 8

Female students -> 10% of 70 = 7

Total students -> 8 + 7 = 15

Total members -> 50 + 70 = 120

Percentage -> 15/120 = 5/40 = 125/10000 = 12.5% or 15/120 x 100% = 12.5%

20.  The graph below shows the number of cakes sold each month by a new bakery from January to June.

How many more cakes were sold in May than in April?

May – 900, April – 650. 900 – 650 = 250

What was the percentage increase in the number of cakes sold in June compared to January? (2014, Paper 2, 3 mark)

June – 950, Jan – 200

Increase -> 950 – 200 = 750

Percentage -> 750/200 = 375/100 = 375% or 750/200 x 100% = 375%

21.

Kim and Hao each bought two books at the sale.

Kim’s books were priced at $8 and $10. How much did she pay for them ?

1^st book -> 90% of $8 = $7.20

2^nd book -> 80% of $10 = $8

Total -> $7.20 + $8 = $15.20

Hao paid a total of $24.80 for his two books. He paid $4 more for 1^st book than for the 2^nd book. What was the price of the 2^nd book before discount? (2014, Paper 2, 5 mark)

2u + $4 = $24.80

2u = $20.80

U = $10.40

2^nd book -> $10.40

80% -> $10.40

20% -> $2.60

100% = $13

HPPS 2015,CA2

On National Day, 12 000 participants took part in the National Day Parade. 60% of the participants were adults and the rest of them were children. 50% of these children wore red T-shirts and the rest of them wore white T-shirts. How many children wore red T-shirts ?

Children -> 40% of 12 000 = 4800

Red T-shirt -> 50% of 4 800 = 2400