A tank is filled in 5 hours by three pipes P, Q and R. The pipe R is twice as fast as Q and Q is twice as fast as P. How much time will pipe P alone take to fill the tank ?

तीन नलों P, Q तथा R द्वारा एक टैंक 5 घंटे में भरता है। नल R, Q से दुगुनी गति से तथा Q, P से दुगुनी गति से चलते हैं, तो अकेले नल P द्वारा टैंक को भरने में कितना समय लगेगा ?

1. A22 hrs22 घंटे
2. B25 hrs25 घंटे
3. C30 hrs30 घंटे
4. D35 hrs 13+ −1335 घंटे +13 −13

Pick an option to check yourself, or open the answer below.

Show answer & explanation

Correct answer: D. 35 hrs 13+ −1335 घंटे +13 −13

Explanation

If P fills x per hour, Q = 2x, R = 4x; 7x = 1/5 → x = 1/35, so P alone takes 35 hours.

P = x, Q = 2x, R = 4x प्रति घंटा; 7x = 1/5 → x = 1/35, अतः P अकेला 35 घंटे।