At a constant Rate of flow, it takes 30 minutes to fill a swimming pool if a large hose is used and 45 minutes if a small hose is Used. At these constant rates, how many minutes will it take to fill the pool when both hoses are used simultaneously?
Choose the correct choice from the following options:  A) 20  B) 22  C) 18  D) 16  E) 14
time taken to fill the pool by Large Hose =30 minutes =L or 1/L=1/30 similarly 1/S=1/45   simultaneously it will take 1/L+1/S=1/30+1/45=5/90=18 minutes   Answer : 18
<result>C</result>
At a constant Rate of flow, it takes 30 minutes to fill a swimming pool if a large hose is used and 45 minutes if a small hose is Used. At these constant rates, how many minutes will it take to fill the pool when both hoses are used simultaneously?