Question
A boat can cover 90 km upstream and 225 km downstream in
15 hours. Speed of the stream is how much less than the speed of the boat in still water if the boat can cover 72 km upstream and 180 km downstream in 12 hours?Solution
ATQ, Let the upstream speed and downstream speed of the boat be x km/h and y km/h, respectively. So according to question: 90/x + 225/y = 15 ………………. (i) Also, 72/x + 180/y = 12 ……….. (ii) Solving (i) and (ii), we get x = 18 and y = 36 So, the upstream speed and downstream speed of the boat are 18 km/h and 36 km/h, respectively. Speed of the boat in still water = (18 + 36)/2 = 27 km/h Speed of the stream = (36 – 18)/2 = 9 km/h So, the desired difference = 27 – 9 = 18 km/h
Six banks were nationalised in 1969 and 14 banks were nationalised in 1980
Dachigam National Park is situated at which of the following states?
 The World’s third largest stadium is to be built in which city of Rajasthan?
In biological terms, _________is a relationship between two organisms in which one organism benefits and the other is unaffected.
The state flower of Haryana is ______.
Who has been recently appointed as the MD & CEO of National Payment Corporation of India (NPCI)?
Which mission received ₹2,104 crore for collecting lunar samples and returning them to Earth?
Which State in India was the largest sugarcane producer (2015-16)?
A student travels on foot up to a distance of 1 (one) km straight in East direction from his school’s entrance gate and after turning at a 90° angle ...
Loktak Lake is located in _______
Relevant for Exams:
