# IGCSE Mathematics Paper-1: Specimen Questions with Answers 21 - 24 of 175

## Question number: 21

### 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,

- So, she received

## Question number: 22

### Describe in Detail

The diagram shows a cylindrical boiler. The radius is 40 cm and the height is 90 cm.

(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,

## Question number: 23

### Write in Short

(a) Find the value of y when .

(b) Make “a” the subject of the formula.

### Explanation

Here, equation is where,

(a)

(b)

## Question number: 24

### Write in Brief

Hema reached at job at and left at . How long, in hours and minutes, did she spend at job?

### Explanation

Here, Hema reached at job at so from 9 to 12 means **3 hours**, from 08: 50 to 9: 00 means **10 minutes**, then another 6: 05 means **6 hours and 05 minutes**.

So, **she spends total of**