#### Answer

9 adults and 2 children.

#### Work Step by Step

Let x be total number of adults, y be total number of children.
System of equations:
x+y=11
22x+15y=228
For first equation, subtract x from both sides: y=11-x
Substitue value of y: 22x+15(11-x)=228
=>22x+165-15x=228 (Distributive property)-> 7x=63 -> x =9 (Combine like terms and simplify)
When x=9, 22(9)+15y=228, then 198+15y=228=> 15y=30=>y=2 (Substitute x to solve for y)