A bus moving at the speed of 45 km/h overtakes a truck 150 m ahead, going in the same direction in 30 sec. The speed of the truck is:

Correct option is B

Given:

Speed of the bus = 45 km/h

Distance to overtake = 150 m

Time taken = 30 seconds

Formula Used:

Distance=Relative Speed × Time

Solution:

​$$45 \times \frac{1000}{3600} = 12.5 \text{ m/s}$$​​

Let truck's speed be x m/s
Then relative speed =12.5 - x

Now, $$150 = (12.5 - x) \times 30$$​

​$$\frac{150}{30} = 12.5 – x$$​​

5 = 12.5 - x

x = 12.5 - 5 = 7.5 m/s

Convert back to km/h

​$$7.5 \times \frac{3600}{1000} = 27 \text{ km/h}$$​