Question

40. Two trains are moving in opposite directions at the speed of 50 and 70 km. per hour. Their lengths are
150 m and 100 m. What is time required for their crossing each other?
(A) 7.5 second
(B) 7.8 second
(C) 8.5 second
(D) 10 second​

Answer 1

Step-by-step explanation:

they are in opposite directions so relative speed

be sum of their speed

realtive speed= 70+50= 120km/hr

= 120×5/18

= 100/3 m/s

total distance= 150+100=250m

time = distance/speed

= 250/(100/3)

= (250×3)/100

= 750/100

= 7.5s

#666