Subject: General Aptitude · Chapter: Number System · Exam: · Marks: · Difficulty:
A number 476**0 is divisible by both 3 and 11. The non-zero digits in the hundred's and ten's place respectively are
(a)7, 4
(b)5, 3
(c)5, 2
(d)None of these
Answer
Answer (as printed): C
Explanation
Let the given number be 476xy0. Then (0 + x + 7) – (y + 6 + 4) = 0 ⇒ x – y – 3 = 0 ⇒ x – y = 3. Also, (4 + 7 + 6 + x + y + 0) = (17 + x + y) must be divisible by 3. Since x ≠ 0, y ≠ 0, so x + y ≠ 1. \ x + y = 4 or 7 or 10 etc. (x + y = 4 and x – y = 3) ⇒ x = 7/2, which is not admissible. (x + y = 7 and x – y = 3) ⇒ x = 5 and y = 2.
Explanation as extracted from the printed page; notation may be imperfect.