Subject
Quantitative Aptitude
Topic
Boat and Stream
A man can row 5 km per hour in still water. If the river is flowing at 1km per hour, it takes him 75 minutes to row to a place and back. How far is the place ?
A man can row 5 km per hour in still water. If the river is flowing at 1km per hour, it takes him 75 minutes to row to a place and back. How far is the place ?
ক)
3 kmখ)
2.5 kmগ)
4 kmঘ)
none of theseExplanation
Let, Distance = x Man's speed u = 5 km/hr stream's speed, v = 1 km/hr; Time taken ( A→B) + Time taken (B←A) = Total time => x/u+v + x/u-v = 75/60 = 5/4 => x/5+1 + x/5-1 = 5/4 => x/6+x/4 = 5/4 => 2x+3x/12 = 5/4 => 5x/12 = 5/4 => x = 5×12/4×5 ∴ x = 3 kmRelated questions
স্থির পানিতে একটি নৌকার গতিবেগ ৮ কিলোমিটার এবং স্রোতের প্রতিকূলে ওই নৌকার গতিবেগ ৫ কিলোমিটার হলে স্রোতের গতি ও স্রোতের অনুকূলে ওই নৌকার গতিবেগ কতA boat can travel with a speed of 13 km/hr in still water. If the speed of the stream is 4 km/hr, find the time taken by the boat to go 68 km downstream.In one hour, a boat goes 11 km/hr along the stream and 5 km/hr against the stream. The speed of the boat in still water (in km/hr) is:The speed of a boat in still water in 15 km/hr and the rate of current is 3 km/hr. The distance travelled downstream in 12 minutes 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 man's speed with the current is 15 km/hr and the speed of the current is 2.5 km/hr. The man's speed against the current is:If a boat goes 7 km upstream in 42 minutes and the speed of the stream is 3 kmph, then the speed of the boat in still water is: (যদি একটি নৌকা স্রোতের প্রতিকূলে 42 মিনিটে 7 কি. মি. যায় এবং স্রোতের গতি 3 কি. মি./ঘন্টা হয়, তাহলে স্থির পানিতে নৌকার বেগ কত?)The ages of Samina and Suhana are in the ratio of 7:3 respectively. After 6 years, the ratio of their ages will be 5:3. What is the difference in their ages ? (সামিনা ও সুহানার বয়সের অনুপাত 7:3 । 6 বছর পরে তাদের বয়সের অনুপাত হবে 5:3 । তাদের বয়সের পার্থক্য কত ?)