Question 979546
Add thir rates of working
Dinesh's rate:
[ 1 job ] / [ 80 min ]
Ramesh's rate:
[ 1 job ] / [ 120 min ]
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let {{{ t }}} = time in minutes to finish
job if they work together
{{{ 1/80 + 1/120 = 1/t }}}
Multiply both sides by {{{ 240t }}}
{{{ 3t + 2t = 240 }}}
{{{ 5t = 240 }}}
{{{ t = 48 }}}
Working together, they can finish job
in 48 minutes
check:
{{{ 1/80 + 1/120 = 1/t }}}
{{{ 1/80 + 1/120 = 1/48 }}}
{{{ .0125 + .008333 = .0208333 }}}
{{{ .020833 = .0208333 }}}
OK