# IGCSE Mathematics Paper-1: Specimen Questions with Answers 30 - 31 of 175

## Question number: 30

### Write in Short

There are approximately 500000 grains of wheat in a 2 kilogram bag.

(a) Find mass of one grain in grams.

(b) Write answer in standard form.

### Explanation

Here,

(a) Here, 500000 grains of wheat in a 2 kilogram bag.

So, 500000 grains = 2000 grams

1 grain =? Grams

So,

(b) Standard form of .

So, for making standard form we need to shift decimal point from left to right three times.

So, it will be: .

## Question number: 31

### Describe in Detail

On a journey a train takes 30 minutes to travel the first 20 kilometers. It then travels a further 40 kilometers in the next 50 minutes.

(a) The train started the journey at 13: 45. At what time did it complete the journey?

(b) Calculate the average speed of the whole journey in

(i) kilometers/minute,

(ii) kilometers/hour.

### Explanation

Here, train takes 30 minutes to travel the first 20 kilometers. It then travels a further 40 kilometers in the next 50 minutes.

(a) Train started the journey at 13: 45.

It takes total

So, it had completed the journey at 13: 45 + 1 hour + 20 minutes = 14: 45 + 20 minutes = 14: 45 + 15 minutes + 5 minutes = 15: 05.

(b) Here total distance =

Total time =

(i) Average speed =

(ii) 60 minutes = 1 hour

80 minutes =? hours

hours

So, average speed =