Question 23 Mahesh can swim in water at 12 km/hr in still water.
Reliance Industries technical mcq question, verified with a worked answer. Free to practise - no sign-up.
Question 23
Mahesh can swim in water at 12 km/hr in still water. If the speed of the stream is 5km/hr, what will be the time taken by the Mahesh to go 68 km downstream?
Show answer & explanation
Answer: C. 4 hours
When swimming downstream, the speed of the swimmer and the speed of the stream are additive. The total downstream speed is 17 km/hr, and dividing the total distance of 68 km by this speed yields 4 hours.
Step-by-step Derivation:
Step 1: Identify the given values.
- Speed of Mahesh in still water (u) = 12 km/hr
- Speed of the stream (v) = 5 km/hr
- Total distance to be covered (d) = 68 km
Step 2: Calculate the downstream speed.
- Downstream speed = Speed in still water + Speed of stream
- Downstream speed = 12 km/hr + 5 km/hr = 17 km/hr
Step 3: Calculate the time taken using the formula Time = Distance / Speed.
- Time = 68 km / 17 km/hr
- Time = 4 hours