Two trains of equal lengths take 10 seconds and 15 seconds respectively to cross a telegraph post. If the length of each train be 120 metres, in what time (in seconds) will they cross each other travelling in opposite direction?
Option
A. 10
B. 12
C. 15
D. 20
Answers
Answered by
1
Answer:
Step-by-step explanation:
the speed of the 1st train = 120/10 = 12 m/s
the speed of the 2nd train = 120/15 = 8 m/s
therefore ,
crossing each other means covering the total distance of two trains
= 120 + 120
= 240 m
and ,
as the train are moving in opposite direction their speed will be = 12 + 8
= 20 m/s
so ,
the time needed to crosses each other = 240/20
= 12 s
therefore , option (b) is the correct answer
Similar questions