Joshua spent 3/7 (as an fraction) of his money on souvenirs on vaction. He has 16$ left how much money does he spend on souvenirs?

Let total amount = x

Amount spent (in fraction) = 3/7x

Total amount left = $16

So equation for this case is:

x - (3/7) x = 16

Multiply both sides by 7

7x-3x=112

4x=112

x=28

So amount spent on souveniers = $28-$16 = $12

Answer: $12