A motor vehicle travelled the first third of a distance s at a speed of v_1=10 kmph, the second third at a speed of v_2=20 kmph and the last third at a speed of v_3=60 kmph. Determine the mean speed of the vehicle over the entire distance s.

A motor vehicle travelled the first third of a distance s at a speed o

1.	A motor vehicle travelled the first third of a distance s at a speed of v_1=10 kmph, the second third at a speed of v_2=20 kmph and the last third at a speed of v_3=60 kmph. Determine the mean speed of the vehicle over the entire distance s.
Answer» 15kmph 12kmph 10kmph 18kmph Answer :D