Subject: General Aptitude · Chapter: Problems on Numbers · Exam: 2003 · Marks: · Difficulty:
The difference between a two-digit number and the number obtained by interchanging the positions of its digits is 36. What is the difference between the two digits of that number?
(a)3
(b)4
(c)9
(d)Cannot be determined
(e)None of these
Answer
Answer (as printed): B
Explanation
Let the ten’s digit be x and unit’s digit be y. Then, (10x + y) – (10y + x) = 36 ⇔ 9 (x – y) = 36 ⇔ x – y = 4.
Explanation as extracted from the printed page; notation may be imperfect.