Question

a man left his home and drove along a certain road at the rate of 48 km/h. one hour later, his son left the same house and drove along the same road in the same direction at 72 km/h. in how many hours does the son overtake the father?

Answer 1

The son overtakes the father 3 hours after the father started driving which is 2 hours after the son started driving.

Explanation:

Father:

speed = 48 km/h

distance = d

time = t

Son:

speed = 72 km/h

distance = d

time = t - 1

speed = distance/time

distance = speed × time

Father:

d = st

d = 48t

Son:

d = st

d = 72(t - 1)

d = 48t

d = 72(t - 1)

48t = 72(t - 1)

48t = 72t - 72

72 = 24t

t = 3

The son overtakes the father 3 hours after the father started driving which is 2 hours after the son started driving.