A 266 m long train passes through a 559 m long tunnel in 66 sec. Find the speed of the train.

Correct option is C

Given:
Train length = 266 m
Tunnel length = 559 m
Time = 66 sec
Formula Used:
Speed = $$\frac{\text{Total Distance}}{\text{Time}}$$​​
Total Distance = Train length + Tunnel length
Conversion: 1 m/s = 18/5 kmph
Solution:
Total Distance = 266 + 559 = 825 m.
Speed in m/s = 825 / 66 = 12.5 m/s.
Speed in kmph = $$12.5 \times \frac{18}{5} = 2.5 \times 18$$ = 45 kmph
So the correct answer is (c)