Algebra & Equations · Question 11 · Medium
The sum of the digits of a two-digit number is 9. When the digits are reversed, the number increases by 27. What is the number?
- 63
- 27
- 36
- 45
Answer and explanation
Answer: C. 36
Explanation: Let the number be 10a + b with a + b = 9. Reversing gives 9(b − a) = 27, so b − a = 3. Hence a = 3, b = 6 and the number is 36.
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