There is a passage in "Arabian Nights": A flock of pigeons, some singing in the trees, some foraging on the ground. A pigeon in the tree said to the pigeons foraging on the ground, "If one of you flies, the pigeons under the tree belong to the whole flock;" If one flies down from the tree, there will be as many pigeons on the tree as under it. " Do you know how many pigeons are on and under the tree?

The ticket prices of city parks are shown in the following table:

The number of ticket buyers is1~ 50,51~ 100, which exceeds100.

Ticket price 10 yuan/8 yuan/5 yuan/person.

More than 50 people from Class A and Class B 100, Grade One in a school, went to the park for a get-together activity, and less than 50 people from Class A and Class B. If you buy tickets according to the schedule, you have to pay them to 920 yuan. If two classes buy tickets together, one class is 5 15 yuan. How many people are there in Class A and Class B respectively?

A shopping mall plans to allocate 90,000 yuan to buy 50 TV sets from manufacturers. It is known that this manufacturer produces three different models of TV sets, the ex-factory price is RMB 0.5 million per set, RMB 2 1.0 million per set, and RMB 2,500 per set. (9 points)

(1) If the shopping mall buys 50 TV sets of two different models at the same time, and it costs 90,000 yuan, please study the shopping plan of the shopping mall;

(2) If a shopping mall sells Class A TV sets, it can make a profit 150 yuan; If it sells a Class B TV, it can make a profit in 200 yuan; If it sells a Class C TV set, it can make a profit in 250 yuan. In the scheme of buying two different TV sets at the same time, which purchase scheme is the most profitable when selling?

A company produces a publicity material, and Company A proposes to charge 20 yuan for each material, with a design fee of 3,000 yuan. Company B proposed that 30 yuan should be charged for each material, and no design fee should be charged. Please calculate which company should the company choose?