Question 1104556
The rate for Enterprise is
[ 1 mission ] / [ 5 yrs ]
Let the rate for Excelsior be
[ 1 mission ] / [ t yrs ]
Their rate transporting together is
[ 1 mission ] / [ 4 yrs ]
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Add their individual rates to get
thei rrate transporting together
{{{ 1/5 + 1/t = 1/4 }}}
Multiply both sides by {{{ 20t }}}
{{{ 4t + 20 = 5t }}}
{{{ t = 20 }}}
Excelsior would take 20 years to
complete mission by itself