Question 961767
A's rate of pumping is {{{ 1/6 }}}
B's rate is {{{ 1/3 }}}
C's rate is {{{ 1/3 }}}
Working together:
{{{ 1/6 + 1/3 + 1/3 = 1/t }}}
Multiply both sides by {{{ 6t }}}
{{{ t + 2t + 2t = 6 }}}
{{{ 5t = 6 }}}
{{{ t = 1.2 }}} hrs
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All 3 pumps are pumping for 1.2 hrs
The fraction of the pool that A pumps
is:
{{{ ( 1/6 )*1.2 = .2 }}}
The fraction that B pumps is:
{{{ ( 1/3 )*1.2 = .4 }}} 
The fraction that C pumps is:
{{{ ( 1/3 )*1.2 = .4 }}}
The fraction of the pool filled by pump A is 1/5