The Arevalo family went out to dinner. The smoky salmon costs $40, the black burger costs $15, and the chicken katsu costs $25. If the bill includes a 10% service charge and 5% tip, how much change will Mr. Arevalo receive from his $100? Let's think first. Chain of thought:
The total amount spent on food is $40 + $15 + $25 = $80. The service charge is $80 x 10 / 100 = $8. The tip is $80 x 5 / 100 = $4. So, Mr. Arevalo had to pay $80 + $8 + $4 = $92 in all. Therefore, his change will only be $100 - $92 = $8.
Therefore, the answer is 8.