SarkariPYQ

SSC Selection Post 2023 PYQ — Question 59

SSC Selection Post - Higher Secondary Level - 28 June 2023 - Shift 2 • Quantitative Aptitude • Q59

Back to paper

Two-thirds of a certain distance was covered at the speed of 15 km/h, one-fifth at the speed of 25 km/h, and the rest at the speed of 50 km/h. Find the average speed (in km/h) for the whole journey (rounded off to two decimal places).

Show answer & explanation

Correct answer: C

Explanation

The correct answer is Option 3 i.e. 18.15.

Let total distance = 15 km

2/3 of distance = 10 km and 1/5 of distance = 3 km

Remaining = 15 - 10 - 3 = 2 km

Average speed =151015+325+250=1562/75=\frac{15}{\frac{10}{15}+\frac{3}{25}+\frac{2}{50}}=\frac{15}{62/75} ≈ 18.15 km/h