Solution: If there are X people, there are 2x+42 trees. From the known 3 (x-1)+1≤ 2x+42 < 3 (x-1)+5, the solution is 40 < x ≤ 44.

X is a positive integer, so X = 4 1, X = 42, X = 43 or X = 44.

When x = 4 1, that is, the number of people is 4 1, the number of saplings is124;

When x = 42, that is, the number of saplings is126;

When x = 43, that is, the number of saplings is128;

When x = 44, that is, the number of people is 44, the number of saplings is 130.