Question 945969
Sally's rate is {{{ 15/4 }}} sheets / min
Eric's rate is {{{ 12/5 }}} sheets/min
Jane's rate is {{{ 7/2 }}} sheets/min
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{{{ 15/4 = 75/20 }}}
{{{ 12/5 = 48/20 }}}
{{{ 7/2 = 70/20 }}}
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In {{{ 20 }}} min:
Add their rates to get rate for {{{ 20 }}} min
{{{ 75/20 + 48/20 + 70/20 = 193/20 }}}
Working together, they can fold {{{ 193 }}} sheets
in {{{ 20 }}} min
Note that {{{ 386 = 2*193 }}}
It will take them twice as long, or {{{ 40 }}} min
to fold {{{ 386 }}} sheets
The answer is (d)