EXPRESSING A NUMBER AS A PERCENTQAGE OF ANOTHER

Problem 1 :

For every 50 students at Hightown School, 29 are girls.

(a) Work out 29 as a percentage of 50.

1000 students attend Hightown School.

(b) How many girls attend Hightown School?

Solution :

(a) Total number of students = 50, number of girls = 29

Expressing it as percentage = 29/50 (Out of 50, 29 are girls)

To convert 50 as 1000, we will multiply 50 by 20, so the numerator also be multiplied by 20. We get

= (29/50) ⋅ (20/20)

= 580/1000

So, 580 girls are there.

Problem 2 :

David receives $5 from his Grandmother. He gives $2 to his sister. Write down $2 as a percentage of $5.

Solution :

Money received from his grand mother = $5

Amount given to his sister = $2

Expressing it as percentage, we get

= (2/5) ⋅ 100%

= 40%

Problem 3 :

Roger scores 6 out of 8 in a quiz. Work out his score as a percentage.

Solution :

Total score = 8, He has scored = 6

Expressing it as percentage,

= (6/8) ⋅ 100%

= 75%

Problem 4 :

Susan brings 500 flapjacks to a local fair. Susan sells 450 of the flapjacks. What percentage of the flapjacks did Susan sell?

Solution :

Number of flapjacks = 500

Number of flapjack he sells = 450

Expressing it as percentage = (450/500) x 100%

= 90%

Problem 5 :

Write 94 out of 200 as a percentage.

Solution :

94 out of 200 = (90/200)

Expressing it as percentage = (90/200) x 100%

= 45%

Problem 6 :

Colin gains 13 out of 20 in a class test. Work out his mark as a percentage.

Solution :

Total score = 20

Collin gains = 13

Expressing as fraction = 13/20

Expressing as percentage = (13/20) x 100%

= (13 x 5) %

= 65%

Problem 7 :

There are 600 people at a football match. There 222 children at the match. Write 222 out of 600 as a percentage.

Solution :

Total number of people = 600

Number of children in the match = 222

Expressing as fraction, we get

= (222/600)

Expressing as percentage = (222/600) x 100%

= 37%

Problem 8 :

Bryan buys a car costing $15000. He pays a deposit $6000. What is $6000 as a percentage of $15000?

Solution :

Cost of car = $15000

Deposit = $6000

Expressing as percentage = (6000/15000) x 100%

= 40%

Problem 9 :

The price of a cinema ticket is reduced from $8 to $7.50 Calculate the reduction as a percentage of the original price

Solution :

Price of ticket = $8

Price of ticket after reduction = $7.50

Difference in price = 8 - 7.50

= 0.50

Expressing the reduction as percentage of original price

= (0.50/8) x 100%

= 6.25%

Problem 10 :

The population of a country is 2.85 x 10⁶. The number of people that own a rabbit is 1.24 x 10⁵. Calculate the percentage of the population that own a rabbit.

Solution :

Total population = 2.85 x 10⁶

People that own rabbit = 1.24 x 10⁵

Percentage of population that own rabbit

= (1.24 x 10⁵)/(2.85 x 10⁶) x 100%

= (124000/2850000) x 100%

= 4.35%