Question

There are 7 empty lockers in a school hallway. in how many different ways could 4 new students be assigned to lockers?

Answer 1

This can be solved using the combination formula C(n,r), where n is the number of objects ( lockers) and r is the sample ( number of students).

There are 7 lockers and 4 students, so it would be written as C(7,4)

= 7! / (4!(7-4)!)

= 7*6*5*4*3*2 / ((4*3*2)*(3*2))
=5040 / (24*6)
=5040/144
=35

There are 35 different ways.