First, let's calculate how much money Trevor spends on the tennis balls. He buys 3 cans at $6 each:
\[ 3 \text{ cans} \times 6 \text{ dollars/can} = 18 \text{ dollars} \]
Now, we subtract the amount he spent on the tennis balls from his total amount:
\[ 65 \text{ dollars} - 18 \text{ dollars} = 47 \text{ dollars} \]
Next, we need to determine how many $8 sports towels Trevor can buy with the remaining $47. To find this, we divide the remaining money by the price of each towel:
\[ \frac{47 \text{ dollars}}{8 \text{ dollars/towel}} \approx 5.875 \]
Since he can only buy a whole number of towels, we round down to the nearest whole number:
Trevor can buy 5 towels.
The correct response is:
5 towels