Choice D is the correct answer. Let $c$ be the number of cars and $t$ be the number of trucks.

Given: $c = 3$ and $3c + 5t = 41$

Step 1: Substitute $c = 3$: $3(3) + 5t = 41$$9 + 5t = 41$

Step 2: Solve for $t$: $5t = 32$$t = \frac{32}{5} = 6.4$

Since we need a whole number, $9 + 5(6) = 9 + 30 = 39 \ eq 41$

Step 1: Substitute $c = 3$: $3(3) + 5t = 39$$9 + 5t = 39$

Step 2: Solve for $t$: $5t = 30$$t = 6$

Solution: 6 trucks were parked.

Verification: $3(3) + 5(6) = 9 + 30 = 39$ ✓

💡 Strategic Tip: When one value is given, substitute immediately to simplify.

Choice A is incorrect because$3(3) + 5(5) = 9 + 25 = 34 \ eq 39$.

Choice B is incorrect because$3(3) + 5(7) = 9 + 35 = 44 \ eq 39$.

Choice C is incorrect because$3(3) + 5(8) = 9 + 40 = 49 \ eq 39$.