Answer:
No sons, three daughters.
Explanation:
They have three children. If they had at least a son (n ≥ 1), there would be three daughters as his sisters (3n). The number of children is represented as 3n + n. If there are no sons, then the three children would all be daughters, but if there was a son, there would be a total of four children consisting of a son and three daughters, which exceeds three (3*1 + 1 = 4, 4 > 3).
