The sum of the digits of a two-digit number is 15 and the difference between the digits is 3. What is the two-digit number ?
Select:
A) 69 B) 78 C) 96 D) Cannot be determined E) None of these
Solution   Let the ten's digit be x and unit's digit be y.   Then, x + y = 15 and x = y =3 or y = x = 3.   Solving x + y = 15 and x - y = 3, we get : x = 9, y = 6.   Solving x + y = 15 and y - x = 3, we get : x = 6, y = 9.   So, the number is either 96 or 69. Hence, the number cannot be determined   Answer Cannot be determined
<result>D</result>
The sum of the digits of a two-digit number is 15 and the difference between the digits is 3. What is the two-digit number ?