Question 697626
Let {{{ x }}} = number of books of {{{ 250 }}} pages
that the machine can copy in {{{ 20 }}} min
Note that {{{ 250x }}} would be the number of pages
that the machine can copy in {{{ 20 }}} min
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The machine's rate of copying is {{{ 100/1 }}} pages / min
I can say that
{{{ 100 / 1 = 250x / 20 }}}
This is just ( pages/min = pages/min )
{{{ 2000 = 250x }}}
{{{ x = 8 }}}
The machine can copy 8 books of 250 pages in 20 min
check:
{{{ 8*250 = 2000 }}}
{{{ 2000 / 20 = 100/1 }}}
OK