Answer:
He spent $12 on souvenirs
Explanation:
Money spent = starting money * fraction spent
Money left = starting money - money spent
Money left = starting money - starting money * fraction spent
Factor out the starting money
Money left = starting money (1- fraction spent)
We know he spent 3/7 of his money and has 16 dollars left
Substitute this information in
16 = starting money (1-3/7)
Change 1 to 7/7 so we have a common denominator
16 = starting money (7/7-3/7)
16 = starting money (4/7)
Multiply each side by 7/4
16 *7/4 = starting money *4/7*7/4
28 = starting money
Now we need to find the money spent
He started with 28 and has 16 left
28-16 = 12
He spent $12 on souvenirs