Problem
Ken and Paul each ordered a sandwich at a restaurant. The price of Ken's sandwich was \( x \) dollars, and the price of Paul's sandwich was \( \$ 1 \) more than the price of Ken's sandwich. If Ken and Paul split the cost of the sandwiches evenly and each paid a \( 20 \% \) tip, which of the following expressions represents the amount, in dollars, each of them paid? (Assume there is no sales tax.)
Solution
Step 1 ：1. \(\text{Price of Ken's sandwich} = x \)
Step 2 ：2. \(\text{Price of Paul's sandwich} = x + 1 \)
Step 3 ：3. \(\text{Total cost} = x + (x + 1) \)
Step 4 ：4. \(\text{Total cost} = 2x + 1 \)
Step 5 ：5. \(\text{Total cost with tip} = (2x + 1) + 0.2(2x + 1) \)
Step 6 ：6. \(\text{Total cost with tip} = 1.2(2x + 1) \)
Step 7 ：7. \(\text{Amount each paid} = \dfrac{1.2(2x + 1)}{2} \)
