2014 · Q50
A certain number of two digits is three times the sum of its digits. If 45 is added to the number, the digits will be reversed. What is the sum of the squares of the two digits of the number?
Elementary MathematicsNumber System
- A41
- B45
- C53
- D64
Explanation
10a + b = 3(a + b) and b − a = 5 give a = 2, b = 7; a² + b² = 53.