+75 The combination locks on the lockers at Hillside School have numbers from 0 through 39 (inclusive). A locker combination consists of three different numbers, where the order matters. Because of the way the locks are manufactured, all three numbers are even or all three numbers are odd. How many combinations are possible?
+37146 20 even numbers 20 odd numbers
20 P 3 + 20 P 3 = 13680 combos
