This is a famous math problem of stealing concepts! Each of them finally spent 10- 1=9 yuan, that is, a * * * spent 9×3=27 yuan. This 27 yuan includes the boss's 25 yuan, the waiter's hidden 2 yuan =27 yuan, and 1 yuan× 3 = 3 yuan, which happens to be 30 yuan. 2 yuan taken away by the waiter is included.