We are simply trying to select any 12 girls from the 24 girls.
Here the order in which the 12 girls are arranged does not matter.
So this is a combination problem.
So the answer is 24 combination 12.
24 Combination 12 = 24! / ((24 - 12!)12!)
= 24! / ( (12!)12!)
= 24*23* 22*21*20*19*18*17*16*25*14*13*12! / (12!12!)
= 24*23* 22*21*20*19*18*17*16*25*14*13 / 12!
Use a calculator.
= 2704156 different groups
