To find out how many more chocolate bars Dennis needs to sell in order to win a prize, we can set up the equation based on his current sales and the target amount he needs to exceed.
- Current Sales: Dennis has already sold $40 worth of chocolate bars.
- Target Sales: He needs to exceed $175.
Let \( x \) be the number of additional chocolate bars Dennis needs to sell. Given that each chocolate bar costs $2.50, the value of the additional bars sold is \( 2.50x \).
The equation can be set up as:
\[ 40 + 2.50x > 175 \]
This equation represents the condition for Dennis to win a prize.