ABC26GN0293 · Number System

Subject: General Aptitude · Chapter: Number System · Exam: · Marks: · Difficulty:

The sum of a number consisting of two digits and the number formed by interchanging the digits is always divisible by

(a)7

(b)9

(c)10

(d)11

Answer

Answer (as printed): D

Explanation

Let the ten's digit be x and the unit's digit be y. Then, (10x + y) + (10y + x) = 11(x + y), which is divisible by 11.

Explanation as extracted from the printed page; notation may be imperfect.