Question 1

LEVEL 3

A dog weighs 48 kg.

After a diet and exercise program the dog weighs 41 kg.

Calculate the percentage change in the dogs’ weight.

Select the correct answer from the list below:

A: 12.1 \%

B: 14.6 \%

C: 10.9 \%

D: 11.3 \%

 

CORRECT ANSWER: B: 14.6 \%

WORKED SOLUTION:

The difference of the dogs current weight compared to its original weight is 48 - 41 = 7.

Hence the percentage change is \dfrac{7}{48} \times 100 =14.6 \%.

Question 2

LEVEL 3

A CD normally costs \pounds15.

It is reduced to \pounds9.75 in a sale.

Calculate the percentage change in the price of the CD.

Select the correct answer from the list below:

A: 30 \%

B: 33 \%

C: 40 \%

D: 35 \%

 

CORRECT ANSWER: D: 35 \%

WORKED SOLUTION:

The difference of the CD sale cost compared to its original cost is given by, 15 - 9.75 = 5.25.

Hence the percentage change is \dfrac{5.25}{15} \times 100 = 35 \%.

Question 3

LEVEL 3

Tony is competing in a Triple jump contest.

His first jump is 11.6 m.

His second jump is 14.5 m.

Calculate his percentage change in jump length.

Select the correct answer from the list below:

A: 20 \%

B: 15 \%

C: 18 \%

D: 25 \%

 

CORRECT ANSWER: D: 25 \%

WORKED SOLUTION:

The difference between the first and second jump is given by , 14.5 - 11.6 = 2.9.

Hence the percentage change is \dfrac{2.9}{11.6} \times 100 = 25 \%.

Question 4

LEVEL 3

Sue deposits £1400 into her bank account which has an interest rate of 2.5 \% per year.

Assuming she does not deposit or withdraw any money, how much money will she have in a years time?

Select the correct answer from the list below:

A: £1435

B: £1428

C: £1425

D: £1420

 

CORRECT ANSWER:         A: £1435

WORKED SOLUTION:

The new total of Sue’s account will be equal to the original amount plus 2.5 \% of the original amount.

To find this, we multiply £1400 by the percentage increase multiplier 1 + 0.025 = 1.025.

Therefore the total value is

£1400 \times 1.025 = £1435

Question 5

LEVEL 3

Mikey has £2600 in his bank account. He decides to withdraw 20 \% of this.

How much money will he have left in his bank account after this withdrawal?

Select the correct answer from the list below:

A: £3120

B: £2080

C: £2000

D: £520

 

CORRECT ANSWER:         B: £2080

WORKED SOLUTION:

The new total of Mikey’s account will be equal to the original amount minus 20 \% of the original amount.

To find this, we multiply £2600 by the percentage decrease multiplier 1 - 0.2 = 0.8.

Therefore the total value is

£2600 \times 0.8 = £2080

Question 6

LEVEL 3

300 pupils attend River bridge school. 35 \% of these pupils bring a packed lunch.

How many pupils bring a packed lunch?

Select the correct answer from the list below:

A: 90

B: 100

C: 105

D: 120

 

CORRECT ANSWER: C: 105

WORKED SOLUTION:

We need to multiply 35 \% as a decimal by 300:

0.35 \times 300 = \dfrac{35}{100} \times 300 = 105 pupils bring a packed lunch.

Question 7

LEVEL 3

25 runners take part in a 5km race. 60 \% of these runners finish the race in under 20 minutes.

How many runners finish the race in under 20 minutes?

Select the correct answer from the list below:

A: 20

B: 18

C: 15

D: 10

 

CORRECT ANSWER: C: 15

WORKED SOLUTION:

We need to multiply 60 \% as a decimal by 25:

0.60 \times 25 = \dfrac{60}{100} \times 25 = 15 runners finish the race in under 20 minutes.