Speed of current is equal to 20% of speed of boat in
still water. If the boat takes 4 hours to cover 120 km in still water, then find the time taken by the boat to cover 96 km in upstream.
A5 hoursCorrect AnswerIncorrect Answer
B2 hoursCorrect AnswerIncorrect Answer
C4 hoursCorrect AnswerIncorrect Answer
D3 hoursCorrect AnswerIncorrect Answer
ENone of theseCorrect AnswerIncorrect Answer
Solution
Speed of the boat in still water = 120 ÷ 4 = 30 km/h Speed of current = 30 × 0.20 = 6 km/h Therefore, upstream speed of the boat = 30 – 6 = 24 km/hr Required time taken = 96 ÷ 24 = 4 hours
