Sharif travelled a distance of 41 km in 9 hours. He travelled partly on foot 3 km/hr and partly on bicycle 9 km/hr. The distance travelled on bicycle is:

Question: Sharif travelled a distance of 41 km in 9 hours. He travelled partly on foot 3 km/hr and partly on bicycle 9 km/hr. The distance travelled on bicycle is:

Solution:
Let,
the distance travelled on bicycle be x km.
distance travelled on foot = (41 -x) km.

ATQ,
Or, (x/9) + (41 − x)/3 = 9
Or, x + 123 − 3x = 81
Or, 2x = 42
Or, x = 21