Question 497629
The rate of filling for the smaller hose is ( 1 pool / 9 hrs)
The rate of filling for the larger hose is ( 1 pool / 2 hrs)
Let {{{t}}} = time to fill pool using both hoses
{{{ 1/9 + 1/2 = 1/t }}}
Multiply both sides by {{{18t}}}
{{{ 2t + 9t = 18 }}}
{{{ 11t = 18 }}}
{{{ t = 18/11 }}}
{{{ t = 1.636 }}} hrs
{{{ .636*60 = 38.182 }}}
{{{ .182*60 = 11 }}}
With both hoses, the pool is filled
in 1 hr 38 min 11 sec