Question

PLEASE ANSWER THIS QUESTION

Train A can cross a 180m long plat form in 90 seconds. Train B has a speed which is twice that of A. A's length is 90% of that of B. B can cross a 200 m long platform in x seconds. Find x.

BRAINLIEST QUESTION

Answer 1

Length of train B = r m
then, length of train A = 90% of B = 0.9r m

speed of train A = Distance covered/time taken
= (length of platform + length of trainA)/time
= (180 + 0.9r)/90
= 2 + 0.01r ........(1)

speed of trainB = distance covered/time taken
= (length of train B + length of platform)/time
= (200 + r)/x......(ii)

A/C to question,
speed of train B = 2 × speed of train A
(200 + r)/x = 2(2 + 0.01r)
(200 + r)/(2 + 0.01r) = 2x
100 = 2x
x = 50

hence,time taken by train B = 50 sec