Question 459887
A train covers a distance in 50 mins, if it runs at at the speed of 36km/hour on the average.
The speed at which the train must run into, reduce the time of journey to 30 mins, will be?
:
Let s = speed required to reduce speed to 30 min
:
Time varies inversely to speed, there for
{{{30/50}}} = {{{36/x}}}
Cross multiply
30x = 50*36
30x = 1800
x = {{{1800/30}}}
x = 60 mph to reduce the time to 30 min
:
:
Check this out using the actual distance
dist = 36*{{{50/60}}}
dist = 30 mi
:
Time going 60 mph: t = 30/60 = .5 hr which is 30 min