Question

one pump can empty a pool in 2 days, whereas a second pump can empty the pool in 11 days. How long will it take the two pumps, working together, to empty the pool?It will take the two pumps ___ days to empty the pool together.

Answer 1

Let x be the number of days it will take the two pump to empty the pool together

`((1)/(2)+(1)/(11))* x=1`
`((11+2)/(22))* x=1`
`(13)/(22)x=1`

Multiply both-side by 22/13

`x=(22)/(13)`
`=1.6923`