Question

A motorcyclist drive from P to Q with uniform speed of 30 kmh–1 and return with a speed of v kmh–1.

If the average speed of the trip is 40 kmh–1, then what is the value of v?​

Answer 1

Answer :- 50 km/h

$\bf\huge\underline{\underline{ Given :- }}$

• $v_{1} = 30 km/h$

• $v_{2} = v km/h$

• $\bar{v} = 40 km/h$

$\bf\huge\underline{\underline{ To \: Find:- }}$

• $v_{2} = v km/h$

$\bf\huge\underline{\underline{ Answer :- }}$

• $\boxed{\bf\bar{v} = \frac{ u + v }{2} }$

• $\red{\implies} \bf 40 = \frac{30 + v}{2}$

• $\red{\implies} \bf 30 + v = 80$

• $\red{\implies} \bf v = 50 km/h$

$\rule{10cm}{0.05cm}$