Question 996305
Add their rates of working:
Call the task:
[ 1 job ]
Mrs. Hensen's rate:
[ 1 job ] / [ 8 hrs ]
Mr. Taylor's rate:
[ 1 job ] / [ 4 hrs ]
Mrs. Phillips' rate:
[ 1 job ] / [ 6 hrs ]
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Let {{{ t }}} = their time if they
all work together
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{{{ 1/8 + 1/4 + 1/6 = 1/t }}}
{{{ 3/24 + 6/24 + 4/24 = 1/t }}}
{{{ 13/24 = 1/t }}}
{{{ t = 24/13 }}}
{{{ t = 1 + 11/13 }}}
{{{ ( 11/13 )*60 = 50.8 }}}
It will take them 1 hr 51 min
if they all work together