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)=20kmph and the last third at a speed of v_(3)=60kmph Determine the mean speed of the vehicle over the entire distances .

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)=20kmph and the last third at a speed of v_(3)=60kmph Determine the mean speed of the vehicle over the entire distances .
Answer» ANSWER :18 KMPH