Question 62780
set this up as two fractions
{{{ 55/100 = x/640 }}}
cross multiply
{{{ 100x = 55(640) }}}
divide both sides by 100
{{{ x = 55(640)/100 }}}
reduce/divide
{{{ x = 55(64)/10 }}}
{{{ x = 11(64)/2 }}}
{{{ x = 11(32) }}}
{{{ x = 352 }}}