Question

The sum of the digits of a two-digit number is 12. The number formed by interchanging the digits is 54 more than the original number. What is the original number? 39 48 57

Answer 1

39

Explanation:

just did test

Answer 2

Let's call the digits of the number ab a and b. Then the information in the question can be expressed as

a+b=12 => b=12-a
a*10+b + 54 = b*10+a => 9a + 54 = 9b

9a + 54 = 9(12-a) => 18a = 54 => a=3

b=12-a; b=9

39 swapped gives 93, 39+54=93