A person travels equal distances at speeds of 3 km/h, 4…

A person travels equal distances at speeds of 3 km/h, 4 km/h, 7 km/h, and 12 km/h, and takes a total of 680 minutes. What is the total distance (in km) travelled?

Show answer & explanation

Correct answer: D

Explanation

The correct answer is option 4 i.e. 56.

Let the distance be 84x

Time = ${84x\over3}+{84x\over4}+{84x\over7}+{84x\over12}$ = 28x + 21x + 12x + 7x = 68x

⇒ 68x = $680\over60$

⇒ x = $1\over6$

Each distance = 84x = 84 × $1\over6$ = 14 km

Total distance = 14 × 4 = 56 km

SSC Selection Post 2022 PYQ — Question 58