Question 976004
Let {{{ a }}} = quarts of solution a to be added
{{{ 2 + a }}} must be {{{ 3/4 }}} of the total solution
{{{ ( 2 + a ) / ( 2 + a + 5 ) = 3/4 }}}
{{{ 4*( 2 + a ) = 3*( 2 + a + 5 ) }}}
{{{ 8 + 4a = 21 + 3a }}}
{{{ a = 21 - 8 }}}
{{{ a = 13 }}}
You must add 13 quarts of solution a
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check:
I can say:
{{{ 5 / ( 2 + a + 5 ) = 1/4 }}}
{{{ 5 / ( 2 + 13 + 5 ) = 1/4 }}}
{{{ 5 / 20 = 1/4 }}}
{{{ 1/4 = 1/4 }}}
OK