Syllabus Edition

First teaching 2021

Last exams 2024

|

Simple & Compound Interest, Growth & Decay (CIE IGCSE Maths: Extended)

Exam Questions

2 hours46 questions
1
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2 marks

Gretal invests $5000 at a rate of 2% per year compound interest.

Calculate the value of her investment at the end of 3 years.


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

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2
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2 marks

Dean invests $500 for 10 years at a rate of 1.7% per year simple interest.
 
Calculate the total interest earned during the 10 years.
 

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

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3
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3 marks

Boris invests $550 at a rate of 2% per year simple interest.
 
Calculate the value of the investment at the end of 10 years.


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

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4
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2 marks

Dina invests $600 for 5 years at a rate of 2% per year compound interest.

Calculate the value of this investment at the end of the 5 years.

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

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5
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3 marks

Scott invests $500 for 7 years at a rate of 1.5% per year simple interest.
 
Calculate the value of his investment at the end of the 7 years.
 

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

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6
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3 marks

The population of a city is increasing exponentially at a rate of 2% each year.
The population now is 256 000.

Calculate the population after 30 years.
Give your answer correct to the nearest thousand.

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7
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3 marks

Roland invests $12 000 in an account that pays compound interest at a rate of 2.2% per year.

Calculate the value of his investment at the end of 6 years.
Give your answer correct to the nearest dollar.

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

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8
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2 marks

Sara invests $500 for 15 years at a rate of 2% per year simple interest.

Calculate the total interest Sara receives.

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

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9
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2 marks

Marlene invests $550 at a rate of 1.9% per year compound interest.
 
Calculate the value of the investment at the end of 10 years.
 

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

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1
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7 marks

Beth invests $2000 at a rate of 2% per year compound interest.

i)
Calculate the value of this investment at the end of 5 years.
    
$ ................................................ [2]
ii)
Calculate the overall percentage increase in the value of Beth’s investment at the end of 5 years.
 
............................................. % [2]
iii)
Calculate the minimum number of complete years it takes for the value of Beth’s investment to increase from $2000 to more than $2500. 
 
[3]

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2
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2 marks

Ollie invests $200 at a rate of 0.0035% per day compound interest.
 
Calculate the value of Ollie’s investment at the end of 1 year.
[1 year = 365 days.]
 

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

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3
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4 marks

The value of a gold ring increases exponentially at a rate of 5% per year.
The value is now $882.

i)
Calculate the value of the ring 2 years ago.

$ ................................................... [2]

ii)
Find the number of complete years it takes for the ring’s value of $882 to increase to a value greater than $1100.

[2]

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4
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3 marks

Mohsin’s earnings increase exponentially at a rate of 8.7% each year.
During 2018 he earned $195 600.

During 2027, how much more does he earn than during 2018?

 

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

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5
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3 marks

Bryan invested $480 in an account 4 years ago.
The account pays compound interest at a rate of 2.1% per year.
Today, he uses some of the money in this account to buy a bicycle costing $430.

Calculate how much money remains in his account.

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

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6
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2 marks

In a city the population is increasing exponentially at a rate of 1.6% per year.
 
Find the overall percentage increase at the end of 20 years.
 

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

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1
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3 marks

Alan invests $200 at a rate of  per year compound interest.
After 2 years the value of his investment is $206.46.
 
Show that     r to the power of 2 space end exponent plus space 200 r space minus space 323 space equals space 0.

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2
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3 marks

The population of a village decreases exponentially at a rate of 4% each year.
The population is now 255.

Calculate the population 16 years ago.

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3
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3 marks

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.
Assume that the population of the Earth increased exponentially by y% each year for these 17 years.
 
Find the value of y.
 

space y space equals space................................................

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4
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3 marks

Edna invests $500 at a rate of r% per year compound interest.
At the end of 6 years, the value of Edna’s investment is $559.78.
 
Find the value of r.
 

r equals...............................................

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5
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2 marks

The value of the campsite has increased exponentially by 1.5% every year since it opened 30 years ago. 

Calculate the value of the campsite now as a percentage of its value 30 years ago.
 

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

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6
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3 marks

The value of Dhanu’s model railway is $550.
This value increases exponentially at a rate of r% per year.
At the end of 5 years the value will be $736.

Calculate the value of r.


 r equals .................................................

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7
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3 marks

Hans invests $550 at a rate of x% per year compound interest.
At the end of 10 years, the value of the investment is $638.30, correct to the nearest cent.

Find the value of x.

x = ..............................................

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8
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3 marks

The population of a village is 6400.
The population is decreasing exponentially at a rate of r space percent sign per year.
After 22 years, the population will be 2607.
 
Find the value of r.
 

r = ....................................................

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9
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3 marks

The number of a particular newspaper sold decreases exponentially by x percent sign each year.
Over a period of 21 years the number of newspapers sold decreases from 1 space 763 space 000 to 58 space 000.

Calculate the value of x
 

x = ..............................................

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10
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3 marks

A bacteria population increases exponentially at a rate of r% each day.
After 32 days, the population has increased by 309%.

Find the value of r.
 

r = .................................................

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11
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3 marks

Over a period of 3 years, a company’s sales of biscuits increased from 15.6 million packets to 20.8 million packets.
The sales increased exponentially by the same percentage each year.

Calculate the percentage increase each year.

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

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12
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6 marks

Tomas has two cars.

i)
The value, today, of one car is $21 000.
The value of this car decreases exponentially by 18% each year.

Calculate the value of this car after 5 years.
Give your answer correct to the nearest hundred dollars.

$ ............................................... [3]
ii)
The value, today, of the other car is $15 000.
The value of this car increases exponentially by x% each year.
After 12 years the value of the car will be $42 190.

Calculate the value of x.

x equals............................................... [3]

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