Question 421064
Let {{{w}}} = gallons of water needed
given:
acid in 2 gallons of 30% solution is {{{.3*2 = .6}}}
{{{ .6/(2 + w) = .2 }}}
{{{ .6 = .2*(2 + w) }}}
{{{ .6 = .4 + .2w }}}
{{{ .2w = .6 - .4 }}}
{{{ .2w = .2 }}}
{{{ w = 1 }}}
1 gallon of water must be added
check:
{{{ .6/(2 + 1) = .2 }}}
{{{ .6/3 = .2 }}}
{{{.6 = .6}}}
OK