Traditional Culture Encyclopedia - Tourist attractions - In order to attract tourists, tourist attractions

In order to attract tourists, tourist attractions

Let's buy x tickets.

Then it is [120-2(X-30)]*X=4000, and the solution is X=40 or X=50.

And because when X=50, the fare is 120-(50-30) * 2 = 80 < 90, which contradicts the main question.

So X=40, which means you bought 40 tickets.

Ticket price:120-(40-30) * 2 =100.