Question

Two identical trains take 3 see to
hass one another when going in
opposite direction. But takes only
2 5 see, if the speed of one is increar!
sed by 50%. The time one would
take to hass the other when going
im same direction at their original
Speed is -
is losec is 12sec u 15 sec ( 8 sec​

Answer 1

Explanation:

both identical trains have speep x and y

and the sum of their length is D

T=D/x+y

when the speed increased 50%

T=D/1.5x+y = 2.5

3x+3y = 3.75+2.5

0.5y=0.75x

y=1.5x

D=3(x+y)=3(2.5x)=7.5x

thus the time train moving in same direction =

D/(x-y) = 7.5x/(1.5x+x)=7.5/0.5= 15 seconds