Question 744030
Add their rates of printing
Let {{{ r }}} = the slower machine's rate of printing
{{{ 2r }}} = the faster machine's rate of printing
When both machines are used, their rate of printing is
( 1 magazine ) / ( 3 hrs )
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{{{ r + 2r = 1/3 }}}
{{{ 3r = 1/3 }}}
{{{ r = 1/9 }}}
{{{ 2r = 2/9 }}}
{{{ 2r = 1/4.5 }}}
The fast machine can print a magazine in 4.5 hrs
The slow machine can print a magazine in 9 hrs