Question

A person covers a certain distance at a certain speed. If he increases his speed by 25%, then he
takes 12 min less to cover the same distance. Find the time taken by him initially to cover the
distance travelling at the original speed.
​

Answer 1

Step-by-step explanation:

ANSWER

Let n ve the event speed

Let T ve the time taken as speed

Let D ve the distance covered in T & x

Given

20minutes=

3

1

hourD=xT

(x+3)

D

=T−

3

1

x−2

D

=T+1/3

Adding the two equations we get

(x+3)(x−2)

D(2x+1)

=2T

(x+3)(x−2)

x(2x+1)

=2

2x

2

+x=2x

2

+2x−12

12=x

∴ Speed 12 km/hr

∴15T=D

18(T−1/3)=D

18T−6=D

3T−6=0

T=2hours

∴ Distance =24cm