If the speed of a train is increased by 20%, its travel time between two stations reduces by 2 hrs. If its speed is decreased by 20%, the travel time increases by 3 hrs. What is the normal duration of travel (in hrs)?

Correct option is B

Given:
· Speed increases by 20%, and time reduces by 2 hours.
· Speed decreases by 20%, and time increases by 3 hours.
Formula: Time = Distance / Speed.
Solution: Let the normal speed of the train be x and the normal time be t.

The distance between the stations is D = x × t.
With a 20% increase in speed: t - 2 = D / 1.2x

Substituting D = x × t: t - 2 = t / 1.2

Simplify: 1.2(t - 2) = t 1.2t - 2.4 = t 0.2t = 2.4 t = 12
Verifying with a 20% decrease in speed: t + 3 = D / 0.8x

Substituting D = x × t: t + 3 = t / 0.8

Simplify: 0.8(t + 3) = t 

0.8t + 2.4 = t

0.2t = 2.4

t = 12

Final Answer: (b) 12.0