x is either 15 or 25 or 35 or 45.sud21 wrote:If x is a two-digit number less than 50 and x=R5, R=? (R is the tens' digit of x)
1) The thousands' digit of x² is 1
2) The hundreds' digit of x² is 2
Hence, x² is either 225 or 625 or 1225 or 2025.
Statement 1: x² must be 1225.
Hence, x must be 35.
Hence, R = 3.
Sufficient
Statement 2: x² is either 225 or 1225.
Hence, x is either 15 or 35.
Hence, R is either 1 or 3.
Not sufficient
The correct answer is A.
