Skip to main content

Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17

Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 23 seconds. The ratio of their speeds is:
A.1 : 3B.3 : 2
C.3 : 4D.None of these





Answer: Option B
Explanation:
Let the speeds of the two trains be x m/sec and y m/sec respectively.
Then, length of the first train = 27x metres,
and length of the second train = 17y metres.
27x + 17y= 23
x+ y
 27x + 17y = 23x + 23y
 4x = 6y
x=3.
y2

Comments

Post a Comment

Popular posts from this blog

It takes 10 days for digging a trench of 100 m long, 50 m broad and 10 m deep. What length of trench, 25 m broad and 15 m deep can be dug in 30 days ?

 It takes 10 days for digging a trench of 100 m long, 50 m broad and 10 m deep.  What length of trench, 25 m broad and 15 m deep can be dug in 30 days ?       a) 400 m          b) 200 m          c) 100 m          d) 89m Expl : More days, more length (Direct)       Less breadth, more length (Indirect)       More depth, less length (Indirect       Days      10 : 30;       Breadth  25 : 50;                  : : 100 : x       Depth    15 : 10;                     :. 10 * 25* 15 * x = 30 *50 * 10 *100             x= (30*50*10*100)/10*25*15 = 400      So the required length = 400m
Post a Comment
Read more