Question

a man walks from his house to his daughter school at a speed of 3 km per hour and returns back at the speed of 4 km per hour if he takes 21 minutes for total journey find the distance between his house and the school...plz tell

Answer 1

let the distance between house and the school be d km
a/q
d/3 +d/4 =21/60
after solving the above equation, we get
d=21/60 *12/7
=0.6 km
=600m