Answer

Verified

411.6k+ views

**Hint:**At first the train needs to cross an electric pole and the distance travelled to cross a pole is the length of the train . Next the train needs to cross a bridge of 80 m , so the distance travelled by the train to cross the bridge is the sum of the length of the bridge and length of the train. The ratio of these two distances give the ratio of the time as distance is proportional to time.

**Complete step-by-step answer:**Step 1:

In the first case the train has to cross an electric pole .

Given that the length of the train is 240 m long .

We know that the length of the train is equal to the distance travelled by the train to cross the electric pole.

Therefore the distance travelled by the train to cross the electric pole = 240 m

Step 2 :

In the second case the train has to cross a bridge of 80 m long

Given that the length of the train is 240 m and length of the train is 80 m

Therefore the distance travelled by the train to cross the bridge is the sum of the length of the train and length of the bridge.

The distance travelled by the train to cross the bridge = 240 + 80 = 320 m

Step 3 :

We know that distance is proportional to time

Hence the ratio of the distances is proportional to the ratio of the time asked.

The ratio is 240 : 320

Simplifying the ratio to bring it to its simplest form we get 3 : 4.

**The correct option is B.**

**Note:**In solving ratio problems we need to make sure that both the quantities are of the same units.

If one quantity is given in metres and another in centimetres then we need to convert both to either metres or centimetres

Recently Updated Pages

The base of a right prism is a pentagon whose sides class 10 maths CBSE

A die is thrown Find the probability that the number class 10 maths CBSE

A mans age is six times the age of his son In six years class 10 maths CBSE

A started a business with Rs 21000 and is joined afterwards class 10 maths CBSE

Aasifbhai bought a refrigerator at Rs 10000 After some class 10 maths CBSE

Give a brief history of the mathematician Pythagoras class 10 maths CBSE

Trending doubts

Difference Between Plant Cell and Animal Cell

Give 10 examples for herbs , shrubs , climbers , creepers

Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE

Fill the blanks with the suitable prepositions 1 The class 9 english CBSE

Name 10 Living and Non living things class 9 biology CBSE

Select the word that is correctly spelled a Twelveth class 10 english CBSE

Change the following sentences into negative and interrogative class 10 english CBSE

Write a letter to the principal requesting him to grant class 10 english CBSE

Write the 6 fundamental rights of India and explain in detail