Question

In a three-digit number, the hundreds digit is greater than 5, the tens digit is greater than 4 but less than 8, and the units digit is the smallest prime number. How many three-digit numbers satisfy all of these conditions?

Answer 1

The hundreds digit can be 6, 7, 8, 9.
The tens digit can be 5, 6, 7.
The units digit is 2.

There are 4 possible digits for the hundreds digit, 3 possible digits for the tens digit, and 1 digit for the ones digit.

The total number of numbers is

4 * 3 * 1 = 12

Answer: 12