The ratio of the lengths of two trains is 7 : 5 and the ratio of their speeds is 9 : 7. Find the ratio of the time taken by them to cross a pole.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 49 : 45.
Length ratio (L1 : L2) = 7 : 5
Speed ratio (S1 : S2) = 9 : 7
Time = Length / Speed
Time ratio = (L1/S1) : (L2/S2) = (7/9) : (5/7) = 49 : 45