Question

Two hoses from two different taps are used to fill a fishpond. The first hose alone

Answer 1

Answer:  12 minutes

Step-by-step explanation:

Two rates for hoses A and B.  FP is the Fish Pond.

A = 20 min/FP   or (1/20)FP/min

B = 30 min/FP   or (1/30)FP/min

The time in minutes, X,  to fill  one FP:

                     1FP = X*((1/20)FP/min) + X*((1/30)FP/min)  

                     1FP = X*(1/20+1/30)FP/min

                     1FP = X*(2.5/30)FP/min

                      X = 12 minutes