Serena took two numbers which may or may not be integers, rounded each of them up to the nearest integer, multiplied the results, and got 100. When she took the original numbers, rounded each of them down to the nearest integer and got X. What is the largest possible value of X?
The largest possible value for X will be when the two integers are the same....this will occur when the first two integers are > 9 but < 10
Rounding them up produces 10 * 10 = 100
Rounding them down produces 9 * 9 = 81 = X