Second-grade intelligence problems
There should be three people, that is, 3 times 9 = 27 yuan, plus the waiter 2 yuan, 27-2=25 is the boss's 25 yuan. There is no 30 yuan, the boss's 25 yuan. That is to say, 25 yuan of the boss+2 yuan of the waiter+3 yuan of the three of them =30 yuan.