Question

if the speed of a car is decreased by 8km/h, it takes 1 hour more to cover a distance of 240 km . find tge original speed of the car​

Answer 1

Step-by-step explanation:

Let s & t be the original speed & time taken.

So s×t = 240

t = 240/s

Also (s - 8)(t+1) = 240

st+s-8t-8 = 240

Applying the value of st & t in above equation

240+s-8×240/s-8 = 240

s -1920/s = 8

s²-1920 = 8s

s²-8s-1920 = 0

(s-48)(s+40) = 0

So s = 48 or -40

Since s can not be negative, s = 48

So original speed of the car is 48 km/hr