Question 23 Mahesh can swim in water at 12 km/hr in still water.
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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
When swimming downstream, the effective speed is the sum of the speed in still water and the speed of the stream. The time taken is calculated by dividing the total distance by this combined downstream speed.
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 (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