Add a chess piece to this problem, which is the common multiple of 3, 5 and 7, between 200 and 300; 3×5×7= 105,

Because it is between 200 and 300, it should be:105× 2-1= 209;

A: There are 209 Go players.

Extended data:

General rules of mathematics examination

When solving a triangle, if it is known that an angle is 60 degrees and its opposite side is 2, then the maximum area and perimeter of the triangle are when the triangle is an equilateral triangle. This law can be strictly deduced.

The big problem of analytic geometry, if the topic is strict geometric relationship, will inevitably be transformed into algebraic relationship, because this is an important test point of analytic geometry.

In arithmetic progression and geometric progression, the tolerance and common ratio are often 2 and 1/2, which is a scoring technique and cannot stand strict scrutiny.

The choice is balanced. In the 12 multiple-choice questions in the math exam, the distribution of Abcd is either three or 2334 division. The college entrance examination questions over the years are suitable.