4. 1 class has 6 boys, 4 girls, and now 3 class leaders need to be selected from them, requiring that there is at least 1 girl among the class leaders, and each person has 1 role, then there are $\qquad$ ways to select.
4. First, calculate all possible selections

There are $10 \times 9 \times 8=720$ ways.
Then calculate the number of ways with no girls selected
There are $6 \times 5 \times 4=120$ ways.
Therefore, there are $720-120=600$ ways in total.