CUET Preparation Today
A man travels from P to Q at the speed of 60 km/h and travels from Q to P at the speed of 90 km/h. What is the average speed of the man for the whole journey? |
75 km/h 78 km/h 70 km/h 72 km/h |
72 km/h |
Average speed = \(\frac{ 2 × S1 × S2}{S1 + S2}\) = \(\frac{ 2 × 60 × 90 }{60 + 90}\) = = \(\frac{ 10800}{150}\) = 72 km/h |
