Tom visited five tourist attractions in Chengdu. Every time he went to a tourist spot, he bought a ticket with a five-dollar foreign exchange certificate, which cost him half the money at that time during the trip. Finally, there is 100 yuan foreign exchange certificate left. So Mr. Tom started.

33553355

Analysis: According to the meaning of the question, if the total foreign exchange starts with X, then the money at the beginning of 2, 3, 4 and 5 scenic spots is x 1, x2, x3 and x4 respectively. According to each point, he spent 5 yuan foreign exchange certificates to buy tickets, which cost half of the money at that time, and finally left 65,438.

According to the meaning of the question:

12(x-5)=x 1，

12(x 1-5)=x2，

12(x2-5)=x3，

12(x3-5)=x4，

12(x4-5)= 100，

The solution is: x4=205, x3=4 15, x2=835, x 1= 1675, x=3355,

So the answer is: 3355. Comments: The key to solve this problem is to make it clear that each browsing point spent half of its own money at that time, and use the method of column equation to find out the amount of money that was not spent at the last scenic spot, and then the original amount of money can be found by backward deduction.

Hope to adopt