We are given a combinatorics problem were we need to find in how many ways 4 cupids can be assigned to 18 empty lockers, this is symbolized as:

Where "n" is the number of objects, in this case, 18 empty lockers, and "r" is the number of cupids. the formula to find this number is the following:

Replacing the known values we get:

Simplifying:

Solving we get:


therefore, there are 3060 ways 4 cupids can be assigned to 18 lockers.