A professor let's his students pick 3 out of 8 assignments to complete. How many combinations of the 3 assignments are possible

It is indeed justifiable that the operation involved in this task is combination because the arrangement of the assignments are not important. The combination may be solved directly from a scientific calculator using the function,

nCr

where in this item the value of n is 8 and that of r is 3. Substituting and solving the combination,

8C3 = 56

Therefore, there are exactly 56 combinations possible.