Subject: General Aptitude · Chapter: Number System · Exam: · Marks: · Difficulty:
A prime number $N$, in the range 10 to 50, remains unchanged when its digits are reversed. The square of such a number is
(a)121
(b)484
(c)1089
(d)1936
Answer
Answer (as printed): A
Explanation
Clearly, 11 is a prime number which remains unchanged when its digits are interchanged. And, $(11)^{2}=121$. Hence, the square of such a number is 121.
Explanation as extracted from the printed page; notation may be imperfect.