Question 949753
Let {{{ x }}} = amount he started with
{{{ x - ( 3/7)*x = 16 }}}
{{{ ( 4/7 )*x = 16 }}}
{{{ x = ( 7/4 )*16 }}}
{{{ x = 28 }}}
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He spent  3/7  of his money on souvenirs
{{{ ( 3/7 )*28 = 12 }}}
He spent $12 on souvenirs