What is the average speed of a car which covers half the distance with a speed of 28 km/h and the other half with a speed of 84 km/h?
42 km/h
Average speed = 2ab ÷ (a + b)
= 2 × 28 × 84 ÷ (28 + 84) = 4704 ÷ 112 = 42 km/h
Important Questions from Speed Time and Distance
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