question_answer

A bird flies with a speed of 10 km/h and a car moves with uniform speed of 8 km/h. Both start from B towards A (BA = 40 km) at the same instant. The bird having reached A, flies back immediately to meet the approaching car. As soon as it reaches the car, it flies back to A. The bird repeats this till both the car and the bird reach A simultaneously. The total distance flown by the bird is

A) 80 km  

B) 40 km

C) 50 km  

D) 30 km

Correct Answer: C

Solution :

\[{{\text{V}}_{\text{L}\text{}}}\text{=8km/h, s=}{{\text{v}}_{\text{0}}}\text{ }\!\!\times\!\!\text{ t}\Rightarrow \text{t=}\frac{\text{40}}{\text{8}}\text{=5h}\]. Total distance flown by the bird\[=10\times 5=50\text{km}\].