Question

Pooja walking at 4 km/hr reaches her school 5 minutes late. If she walks at 5 km/hr, she will reach her school 4 minutes early. Find the distance of her school from her residence

Answer 1

let the distance b x km
time taken at 4 km/h = x/4
time taken at 5 km/h = x/5

but the difference in those two times is 9 minutes
or 9/60 hrs = 3/20 hrs

x/4- x/5 = 3/20
times 20, the LCD
4x - 4x = 3
x = 3

She lives 3 km from school