Subject
Quantitative Aptitude
Topic
Speed & Distance
Ishwar is rowing a boat. He takes half time in moving a certain distance downstream than upstream . What is the ratio of the rate of boat in still water to the rate of current ?
Ishwar is rowing a boat. He takes half time in moving a certain distance downstream than upstream . What is the ratio of the rate of boat in still water to the rate of current ?
ক)
2 : 1খ)
5 : 1গ)
7 : 1ঘ)
3 : 1Explanation
Let, Speed of the boat u and speed of current v We have to find out u : v ? If x distance is covered then time for downstream is = {x/(u+v)} and time for upstream is = {x/(u-v)} According the question, {x/(u+v)} = [(1/2){x/(u-v)}] => {(u+v)/(u-v)} = 2 => u + v = 2u - 2v => u - 2u = -2v - v => -u = -3v =>u/v = 3/1 ∴ u : v = 3 : 1Related questions
A man takes twice as long to row a distance against the stream as to row the same distance in favour of the stream. The ratio of the speed of the boat (in still water) and the stream is:Speed of a boat in standing water is 9 kmph and the speed of the stream is 5 kmph. A man rows to a place at a distance of 105 km and comes back to the starting point. The total time taken by him is:two trains are moving in opposite directions at 60 km/hr and 90 km/hr. Their lengths are 1/10 km and 9 km respectively. The time taken by slower train to cross the faster train in seconds is -A man can row three-quarters of a kilometre against the stream in 11×(1/4) minutes and down the stream in 7×(1/2) minutes. The speed (in km/hr) of the man in still water is:In a 300 m race A beats B by 5 metre or 6 seconds. B's time over the course is -A boatman goes 2 km against the current of the stream in 1 hour and goes 1 km along the current in 10 minutes. How long will it take to go 5 km in stationary water?A boat covers a certain distance downstream in 1 hour, while it comes back in 1x(1/2) hours. If the speed of the stream be 3 kmph, what is the speed of the boat in still water?A man buys tk 20 shares paying 9% dividend. The man wants to have an interest of 12% on his money. The market value of each share is-