Question { IBM, 18904 }

If a car starts from A towards B with some velocity.Due to
some problem in the engine after travelling 30km, the car
goes with 4/5 th of its actual velocity The car reaches B
45 min later to the actual time.If the car engine fails
ofter travelling 45km, the car reaches the destination B
36min late to the actual time .What is the initial velocity
of car and what is the distance between A and B in km ?

Answer

Let divide the question in two parts:-
1:-travelling at 4/5th of actual speed from the problem point car is late by 45 min.
2:That is clear it will take 9 min less to cover up the distance with actual speed if car fails after 45 km.
soln:-
difference in 1st cond and second condition is 15 km and 9 min
if car travels with 4/5th speed it will take 5/4 time of actual means 1/4 time more than actual
but here only 9mins more so actual time =36 min
to cover up 15 km in 36 min
speed=15/(3/5)
speed=25km/hr
from second,it is late by 45 min with 4/5 speed
so 1/4 more than actual so
actual time would be= 180 min=3hr
25*3=75km from problem point
so total distance is=30+75=105km