Two hoses are pouring water into an empty pool. Hose 1 alone would fill up the pool in 6 hours. Hose 2 alone would fill up the pool in 5 hours. How long would it take for both hoses to fill up two-thirds of the pool?	Choose the correct option.
A) 5/12 hours  B) 5/8 hours  C) 20/11 hours  D) 12/7 hours  E) 12/5 hours
Hose 1 would fill the pool alone in 6 hours   i.e. 1 Hour work of Hose 1 = 1/6   Hose 2 would fill the pool alone in 5 hours   i.e. 1 Hour work of Hose 2 = 1/5   i.e. 1 Hour work of Hose1 and Hose2 together = (1/6)+(1/5) = (11/30)   i.e. (11/30) work can be finished by Hose1 and Hose2 together in 1 hour   i.e. (2/3) work can be finished by Hose1 and Hose2 together in 1*(30/11)*(2/3) = 20/11hour   Answer: Option 20/11 hours
<result>C</result>
Two hoses are pouring water into an empty pool. Hose 1 alone would fill up the pool in 6 hours. Hose 2 alone would fill up the pool in 5 hours. How long would it take for both hoses to fill up two-thirds of the pool?