| The first and third number are the same, and the second one can be anything.
The only constraint on the first/third number is that it cannot be equal to zero, or else it would not be a three digit number. So there are 9 possibilities (1 through 9).
There are no constraints on the second number. So there are 10 possibilities.
How many combinations are there? 9 x 10 = 90. The answer is C. |