Permutation and combination problem

"Boy A was selected and girl B was not selected for c3 1c62. One of the other three girls was guaranteed, and two of the remaining six boys and girls were chosen. . "The mistake is that if two of the remaining six boys and girls are selected and there are girls, then the girls who are selected twice have priority. This is not a combination, but an arrangement. The correct one should be: C73-C43, that is, take three of the remaining four boys and three girls, subtract three of the remaining four boys, and ensure that there are at least 1 girl among the selected three. The boy A was not selected, and the girl B was also selected, which should be C73-C33.

So (C73-C43)+(C73-C33)+C72=86, at least 1 boys and girls were selected.