Question 729515
Here are set-ups:
(1)
Let {{{ a }}} = gallons of 15% alcohol needed
Let {{{ b }}} = gallons of 30% alcohol needed
given:
{{{ a + b = 30 }}}
{{{ ( .15a + .3b ) / 30 = .25 }}}
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(2)
Let {{{ n }}} = number of nickels in box
Let {{{ d }}} = number of quarters in box
given:
{{{ n + d + q = 85 }}}
{{{ n = 3d }}}
{{{ 5n + 10d + 25q = 625 }}} ( in cents )