Q. Motor-cyclist P started his journey at a speed of 30 km/hr. After 30 minutes, motor cyclist Q started from the same place but with a speed of 40 km/hr. How much time will Q take to overtake P?
Answer: $latex \frac{3}{2}\ hours&s=1$
Notes: Distance covered by motor cyclist P in 30 minutes. $latex = 30\times \frac{1}{2} = 15\ km&s=1$ Relative Speed = 40 - 30 = 10 km/hr ∴ Required Speed = Time taken to cover is km at 10 km/hr $latex = \frac{15}{10} = \frac{3}{2}\ hours&s=1$ Hence option [C] is correct answer.

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