8. Solution: Suppose Lao Zhang bought X rabbits a year ago. According to the meaning of the question. X+≤2/3(2x- 1), and x≥8.
Lao Zhang bought at least eight rabbits a year ago.
9. Solution: Let three consecutive positive integers be (x- 1), x, (x+ 1). According to the meaning of the question, the solution of (x-1)+x+(x+1) < 3331is x <1. And because x- 1 is a positive integer, X- 1 > 0, X > 1, so 1 < X < 1 1, so take x as 165438+.
A: There are 109 groups in this positive integer * *, and the largest group is 109, 1 1.