Percentages Toolkit (CIE IGCSE Maths: Extended)

A bag contains 54 red marbles and some blue marbles.
36% of the marbles in the bag are red.

Find the number of blue marbles in the bag.

Arjun earned $36 515 in 2019.
This was an increase of 9% on his earnings in 2018.

Work out his earnings in 2018.

$ ................................................

In a sale the original prices are reduced by 15%.
 
Calculate the original price of a jacket that has a sale price of $38.25.
  

$ .................................................

In September the total income at a campsite was $37 054.
This was a decrease of 4.5% on the total income in August.

Calculate the total income in August.
 

$ .................................................

The cost of a railway magazine increases by 12.5% to $2.70.

Calculate the cost of the magazine before this increase.

$ .................................................

In a sale, Ali buys a television for $195.80.
The original price was $220.

Calculate the percentage reduction on the original price.

................................................ %

Apples cost Mohsin $0.85 per kilogram to produce. He sells them at a profit of 60%.

Work out the selling price per kilogram of the apples.

$ ...................................................

The price of a book increases from $2.50 to $2.65 .
 
Calculate the percentage increase.
 

............................................... % 

The price of a newspaper increased from $0.97 to $1.13 .
 
Calculate the percentage increase.
 

........................................... %

The fares for the train journey are shown in the table below.

For an adult, find the percentage increase in the cost of the standard fare to the premier fare.
 

........................................... %

In a sale, Marianne buys a new camera for $483.
This is a reduction of 8% on the original price.
 
Calculate the original price of the camera.
 

$ ..............................................

............................................ % [3]

........................... litres/second [3]

Since a school was opened, the number of students has increased by 60%.
There are now 240 students.
 
Calculate the number of students when the school was opened.

The price of a house decreased from $82 500 to $77 500.

Calculate the percentage decrease.

............................................ %

In 2017, the membership fee for a sports club was $79.50.
This was an increase of 6% on the fee in 2016.

Calculate the fee in 2016.

$ ..............................................

A company makes biscuits at a cost of $1.35 per packet.
These biscuits are sold for $1.89 per packet.

............................................ % [3]

$ ................................................ [3]

Rowena buys and sells clothes.

The selling price of dress fabric is $2.97 per metre, which is an increase of 8% on the cost price.
  
Calculate the cost price.
 

$ ............................... per metre

There were passengers that made a journey in 2018.
This was a 12% decrease in the number of passengers that made this journey in 2017.

Find the number of passengers that made this journey in 2017.
Give your answer in standard form.

In the sale, Mo buys a jacket for $63.
The original price was reduced by 25%.

Calculate the original price of the jacket.

$ ...................................................

In a sale the original prices are reduced by 15%.

Calculate the sale price of a book that has an original price of $12.
 

$ .................................................

Dhanu has a model railway.

He has a train that consists of a locomotive and 4 coaches.
The mass of the locomotive is 87 g and the mass of each coach is 52 g.

.............................................. g [2]

............................................. % [1]

Manjeet uses 220 litres of water each day.
She reduces the amount of water she uses by 15%.

Calculate the number of litres of water she now uses each day.

......................................... litres

A school has 240 students.
Next year, the number of students will increase by 15%.

Calculate the number of students next year.

One month, Gretal spent a total of $360 on presents.
She spent  of this total on presents for her parents.
She spent  of the remaining money on presents for her friends.
She spent the rest of the money on presents for her sisters.

Calculate the percentage of the $360 that she spent on presents for her sisters.

............................................. % 

The table shows the surface area of some countries and their estimated population in 2017.

Find the surface area of France as a percentage of the surface area of China.

 ............................................. %

The population of the Earth in 2017 was estimated to be 7.53 × 10⁹.

The population of the Earth in 2000 was estimated to be 6.02 × 10⁹.

Work out the percentage increase in the Earth’s estimated population from 2000 to 2017.

 ............................................. %

Marianne sells photos.
The selling price of each photo is $6.

Marianne makes a profit of $2.25 on each photo.
Calculate her profit as a percentage of the selling price.

............................................%

At time t = 0 hours a tank is full of water.

Water leaks from the tank.
At the end of every hour there is 2% less water in the tank than at the start of the hour.

The volume of water, in litres, in the tank at time t hours is V_t
Given that
V_o = 2000
V_{t + 1} = kV_t
write down the value of k.