Question

If The Speed Of A Car Is Increased By 10km Per Hr It Takes 18min Less To Cover A Distance Of 36km.Find The Speed Of The Car

Answer 1

let the speed of car is x and t is perfect time in which he reach target position.
now
36/x=t hour----------------(1)
36/(x+10)=(t-18/60) hour--------------(2)
solve both equation
x=30km/h
hence speed of car is 30km/h

Answer 2

speed = x
time = t
x + 10 = 36 ÷ t - 18
as 18 min = 3÷10 hours
so ,
x+10=360÷10t -3
and we know , x=36÷t
36÷t + 10 =360÷10t-3
on solving ,
100 t^2-30t-108=0
solve it to get the answer