How many seconds will a train 60m in length, travelling at the rate of 42km/hr take to pass another train 84m long, proceeding in the same direction at the rate of 30km/hr.
- 20
- 32
- 43.2
- 40
- Explanation:
Relative speed=42-30=12km/hr=12*(5/18)
Length=60+84=144m
Time=144*18/12*5=(12*18)/5=216/5=43.2s