Working alone, pump A can empty a pool in 3 hours. Working alone, pump B can empty the same pool in 2 hours. Working together, how many minutes will it take pump A and pump B to empty the pool?
বিকল্পসমূহ (নিজের উত্তর যাচাই করতে ক্লিক করুন):
সঠিক উত্তর
ক (72)
বিস্তারিত ব্যাখ্যা ও বিশ্লেষণ:
Solution:
Pump A can empty the pool in 3 hours therefore the rate at which it empties is 1/3 pool/hour
Pump b can empty the pool in 2 hours therefore the rate at which it empties is 1/2 pool/hour.
If they work together, the resulting rate is the addition of both rates (1/3 +1/2)pool/hour
= 5/6 pool/hour
So, time taken by both pipe to empty the pool = 6/5 hr
= (6/5) × 60 minutes
= 72 minutes
