# IGCSE Mathematics Paper-1: Specimen Questions with Answers 19 - 22 of 175

## Question number: 19

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### Write in Short

Solve the equations

(a) ,

(b)

Here,

(a)

(b)

## Question number: 20

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Essay Question▾

### Describe in Detail

The population of a city is . It is expected that this population will increase by 42 % by the year 2008. Calculate the expected population in 2008.

### Explanation

Here, Population is.

Expected population will increase by 42%.

So, increment in population will: .

So, expected population will be

## Question number: 21

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### Write in Short

Jerry changed \$20 into euros with exchange rate was €1= \$1.2685. How many euros did she receive? Answer in 2 decimal places.

### Explanation

Here, €1= \$1.2685.

• Jerry changed \$20 into euros.
• Where, exchange rate was

So,

## Question number: 22

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Essay Question▾

### Describe in Detail

The diagram shows a cylindrical boiler. The radius is 40 cm and the height is 90 cm. A Cylindrical Boiler Showing Radius and Height Find the below given calculations by using given values of cylinder

(a) Calculate the area of the base of the boiler.

(b) Calculate the volume of the boiler in liters.

### Explanation

Here, radius is 40 cm and height is 90 cm.

(a) Area of base of the boiler is a circle, so by using the formula of area of a circle:

(b) Volume of the cylindrical boiler:

Now,

So,

So,