A group of 16 people bought tickets to a museum. They paid a total of $56. Each adult ticket costs $4 and each child ticket costs $2. How many adult tickets and child tickets did they buy.

12 adult tickets, 4 child tickets

8 adult tickets, 8 child tickets

10 adult tickets, 6 child tickets

4 adult tickets, 12 child tickets

10 adult tickets, 6 child tickets

Let x be the number of adult tickets and y be the number of child tickets.
From the information given, we have the following equations:
x + y = 16 (total number of tickets)
4x + 2y = 56 (total cost of tickets)

Solving the system of equations, we get:
x = 10
y = 6

Therefore, they bought 10 adult tickets and 6 child tickets.