6.There are two women participating in a class tournament. Every participant played two games with the other participants. The number of games that the men played between themselves proved to exceed by 66 the number of games that the men played with the women. The number of participants is

7.The total number of seven-digit numbers, the sum of whose digits is even, is

8.The number of five digit telephone numbers having at least one of their digits repeated is

9.In a plane there are 37 straight lines, of which 13 pass through the point A and 11 pass through the point B.Besides, no three lines pass through one point, no line passes through both points A and B, and no two are parallel. Then the number of intersection points the lines have is equal to

10.The number of triangles whose vertices are at the vertices of an octagon but none of whose sides happen to come from the sides of the octagon is