Question

.A train covers a certain distance at a uniform speed . On increasing its speed by 5 km/hr it saves 20 minutes and on decreasing its speed by 20 km/hr it loses 2 hrs. Find the distance covered by the train

Answer 1

.A train covers a certain distance at a uniform speed . On increasing its speed by 5 km/hr it saves 20 minutes and on decreasing its speed by 20 km/hr it loses 2 hrs. Find the distance covered by the train

Answer 2

Step-by-step explanation:

Let the time taken be t,

and speed be x.

i.e., distance = xt

In case 1

 time = t1

time = xt / x + 10                    (time = distance / speed)

xt / x + 10 = t - 2

xt = (t - 2 ) (x + 10)

xt = xt + 10t - 2x - 20

xt and xt get cancelled

10t - 2x - 20 = 0                   ... equation 1

In case 2

 t2 = xt / x- 10

xt / x - 10 = t + 3

xt = (t + 3) (x - 10)

 xt = xt - 10t + 3x - 30

 xt and xt get cancelled

-10t + 3x - 30 = 0                  .... equation 2

now u can solve this by using any 1 method i.e, substitution, elimination or cross-multiplication.