Three students went to the hotel, and according to the regulations, the boss received a deposit of RMB 100 each (***300 yuan). Afterwards, the boss felt that the students were also very hard, so he took out 50 yuan and asked the secretary to return it to them. The secretary took the money and thought that 50 yuan was not good at scoring, so she deducted 20 yuan and gave them each 10 yuan. So, so, every college student only paid 90 yuan.

Question: Three college students each paid 90 yuan, three were 270 yuan and 20 yuan, and 290 yuan was detained by the secretary, so where did the other 10 yuan go?