Question

amitabh sees uma standing at a distance of 200m from his position.he increases his speed by 50% and hence takes 20s now to reach her.(a) if he travels at original speed,how much time will he take?(b) what was his original speed(in km/h)? (c) what is his new speed?

Answer 1

Let original speed be x
t=d/s
20=200/(s*150/100)
20*s*15=2000
s=20/3 m/s
new speed = 20/3*150/100
=10m/s
t at original speed =d/s
t=200/20/3
30s

Answer 2

let his original speed be X
distance =200 m
now his new speed increase by 50% which will be 1.5X
and tIme cover by him is 20s

speed ×time = distance
1.5X ×20 = 200
1.5X = 10
X = 6.66 m/s
on converting into km/h
$x = \frac{6.66 \times 1000}{3600}$
X = 1.85 km/h
and his new speed =1.5×1.85
= 2.775 km/h