A car travels from calabar to Enugu, a distance of P km with an average speed of U km per hour and continues to benin, a distance of Q km, with an average speed of Wkm per hour. Find its average speed from Calabar to Benin
A. \(\frac{(p + q)}{pw + qu}\) B. \(\frac{uw(p + q)}{pw + qu}\) C. \(\frac{uw(p + q)}{pw}\) D. \(\frac{uw}{pw + qu}\)
Correct Answer: B
Explanation
Average speed = \(\frac{\text{total Distance}}{\text{Total Time}\) from Calabar to Enugu in time t1, hence t1 = \(\frac{P}{U}\) also from Enugu to Benin t2 \(\frac{q}{w}\) Av. speed = \(\frac{p + q}{t_1 + t_2} = \(\frac{p + q}{\frac{p}{u} + \frac{q}{w}\) = p + q x \(\frac{uw}{pw + qu}\) = \(\frac{uw(p + q)}{pw + qu}\)
