A locker combination has three nonzero digits and digits cannot be replaced. The first two digits are 9 and 8. What is the probability that the third digit is 7?

1 in 7

Step-by-step explanation:

Your one-digit choices: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

But they're nonzero, so: 1, 2, 3, 4, 5, 6, 7, 8, 9.

But they can't be repeated and 9 and 8 are used, so: 1, 2, 3, 4, 5, 6, 7.

Only 7 numbers left, so chances are, 1 in 7.