Give the step-by-step reasoning process and then the final answer. There are 3 bicycles, 4 tricycles and 7 unicycles in the garage at Zoe's house. Each bicycle has 2 wheels, each tricycle has 3 wheels and each unicycle has 1 wheel. How many wheels are there in all?
The number of bicycle wheels is 2 × 3 = 6. The number of tricycle wheels is 3 × 4 = 12. The number of unicycle wheels is 1 × 7 = 7. The total number of wheels is 6 + 12 + 7 = 25.
The final answer: 25.