Multiple choice

The ratio of time to going certain distance in down stream and upstream is 2 : 5. Then find the ratio of speed of boat in still water to speed of stream ? किसी निश्चित दूरी को अनुप्रवाह तथा उर्ध्वप्रवाह में लगे समय का अनुपात 2 : 5 हैं तो शान्त जल में नाव की चाल तथा धारा की चाल का अनुपात क्या होगा ?

  1. 2 : 5

  2. 5 : 2

  3. 3 : 5

  4. 7 : 3
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Given time ratio (downstream:upstream) = 2:5. Since distance is constant, speed ratio is inverse: (b+s)/(b-s) = 5/2. Cross-multiply: 5b+5s = 2b-2s. Solving: 3b = 7s, so b:s = 7:3. Option D is correct.

Keep practicing — related questions