The sum of the two digits of a two-digit number is 13 and the number obtained by interchanging the two digits is 27 less than the original number. What is the original number?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1. i.e. 85.
Let the unit digit be b and the tens digit is a.
According to the question;
a + b = 13 ------ (1)
Two digit number = 10a + b
After interchanging = 10b + a
10b + a = 10a + b - 27
b - a = 3 ------- (2)
Solving equation 1 and 2;
a = 8 and b = 5
Hence, the original number is 85.