To find out how many bags of popcorn Damari needs to sell to reach his goal of $85, we can set up the equation based on his current amount of money and the price per bag.
- Current amount: $40
- Goal: $85
- Price per bag: $3
First, we calculate how much more money he needs to reach his goal:
\[ \text{Amount needed} = \text{Goal} - \text{Current amount} = 85 - 40 = 45 \]
Now, we can find out how many bags he needs to sell to raise this amount. Since each bag costs $3, we divide the additional amount needed by the price per bag:
\[ \text{Number of bags} = \frac{\text{Amount needed}}{\text{Price per bag}} = \frac{45}{3} = 15 \]
Therefore, Damari needs to sell 15 bags of popcorn to reach his goal of $85.
The correct response is: 15.