A boat goes 24 km uptream in one hour more than the time taken to cover the same distance downstream. If the speed of the current of the river is 2 km/h, then what is the speed (in km/h) of the boat in upstream travel?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 8.
Given:
A boat goes 24 km upstream in one hour more than the time taken to cover the same distance downstream.
Speed of current = 2 km/h
Formula used:
Speed = distance/time
Calculations:
Let the speed of boat be x;
Upstream speed = x - 2
Downstream speed = x + 2
According to the question,
⇒ 24/(x - 2) - 24/(x + 2) = 1
⇒ 24(x + 2 - x + 2) = x2 - 4
⇒ 24 × 4 = x2 - 4
⇒ x2 = 96 + 4
⇒ x2 = 100
⇒ x = 10
Hence,
Speed of boat in upstream = x - 2 = 10 - 2 = 8 km/h