The solution to the problem is as follows:
If there are 6 pairs of shoes:
C(6,1) = choose the matching pair = 6 choices.
C(10,1) = 1 shoe from the other 10.
Now you cannot choose the mate of that one,
so you have 8 other shoes to choose from.
6 * 10 * 8 = 480 choices of "4 shoes".
But then we must divide by 2, because the last two shoes
could be chosen in either order.
That gives 240 choices - same as your teacher's answer,
but via a different route.
I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!
