From a group of 7 boys and 6 girls, five persons are to be selected to form a team, so that at least 3 girls are there in the team. In how many ways can it be done?

Given in the question that, there are 7 boys and 6 girls. 

Team members = 5

Now, required number of ways in which a team of 5 having atleast 3 girls in the team = 

$6C3 x 7C2 + 6C4 x 7C1 + 6C5= \frac{6x5x4}{3x2x1} x \frac{7x6}{2x1} + \frac{6x5x4x3}{4x3x2x1} x 7 + \frac{6x5x4x3x2}{5x4x3x2x1}= 420 + 105 + 6= 531.$