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SSC GD 2023 PYQ — Question 44

SSC GD Constable (English) - 30 Jan 2023 - Shift 1 • Quantitative Aptitude • Q44

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 A car travels 13\frac{1}{3} of the distance on a straight road at a speed of 10 km/h, the next 13\frac{1}{3}at a speed of 20 km/h, and the last 13\frac{1}{3} at a speed of 60 km/h. Find the average speed of the car.

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Correct answer: A

Explanation

The Correct answer is option 1 i.e. 18 km/h.

Speed = Distance/time

Let's assume the total distance = 90 km

 90 × 13\frac{1}{3}  = 30 km

Time at a speed of 10 km/h:

Time = 30/10 = 3 hours

Time at a speed of 20 km/h:

Time = 30/20 = 1.5 hours

Time at a speed of 60 km/h:

Time = 30/60 = 0.5 hours

Total time = 3 + 1.5 + 0.5 = 5 hours

Average speed = Total distance/Total time = 90/5 = 18 km/h