Question

Sushant rides his bicycle at the speed of 2 km per hour he reaches his School late by 1 minute on increasing the speed by 2 kilometre per hour he reaches 5 minutes early find the distance between His school and his house

Answer 1

let school time be x 
if he rides by 2 km /hr
 distance = speed x time
                =2 x( x + 1)
                =2x + 2
speed increased by 2 km ;speed = 4km/hr
 distance = 4 x (x - 5)
               =4x-20
we know that the distance in both cases is same
 so 2x+2 = 4x -20
     2 + 20=4x-2x
     2x =22
    x = 11
 distance is 2x + 2 ( or 4x - 20)
                distance=(2 x 11) + 2
                              =22+2
                          distance    =24km

Answer 2

at speed of 2km/hr ,he is late by 1 minute

after increasing his speed by 2km/hr , his speed is 4km/hr (2+2) he is earlier by 5 minute

distance = (product of two speed/ difference of two speed )* difference in time arrival

distance= (2 * 4 / 2) *( 6 / 60)

distance = 4/10 or 400m.