Multiple choice

A boat travels 24 km upstream in 6 hours and 20 km downstream in 4 hours. Then, what is the ratio of the speed of the boat in still water and the speed of the current? एक नाव 6 घंटे में 24 किमी. ऊर्ध्वप्रवाह और 4 घंटों में 20 किमी. अनुप्रवाह यात्रा करती है । तो, स्थिर जल में नाव की गति का धारा की गति से क्या अनुपात है?

  1. 4 : 3

  2. 5 : 2

  3. 9 : 1

  4. 2 : 1

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Upstream: speed = 24/6 = 4 km/hr (boat - current). Downstream: speed = 20/4 = 5 km/hr (boat + current). Adding: 2 × boat speed = 9, so boat = 4.5 km/hr. Subtracting: 2 × current = 1, so current = 0.5 km/hr. Ratio = 4.5 : 0.5 = 9 : 1. Option C matches.