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?

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

12

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.