To determine the number of games, \( x \), that Sheila played at the fair, we need to account for the total amount she spent. Sheila spent $16 on a ticket and $3 for each game she played. The total amount spent is $40.
The correct equation can be set up as follows:
- Start with the total spent: $40.
- Subtract the cost of the ticket: $40 - $16 = $24.
- The remaining amount ($24) is the total spent on games, where each game costs $3.
Letting \( x \) be the number of games played, we can represent the amount spent on games as \( 3x \). Thus, we can write the equation:
\[ 3x + 16 = 40 \]
So the correct choice is:
3x + 16 = 40