List all 2-digit prime numbers, in which both the digits are also prime numbers.

Let ab, a ne b , is a 2-digit prime number such that ba is also a prime number. The sum of all such number is: ab,(a ne b) एक 2-अंकीय अभाज्य संख्या है जैसे कि ba भी एक अभाज्य संख्या है। ऐसी सभी संख्याओं का योग है

List out all the 2-digit prime numbers which are greater than 50.

(i) Write the smallest prime number. (ii) List all even prime numbers. (iii) Write the smallest odd prime number.

Total number of 6-digit numbers in which all the odd digits appear, is

List out all the 2-digit twin primes.

How many two digit prime numbers are there between 10 to 100 which remains prime numbers when the order of their digits is reversed?

With a two digit prime number , if 18 is added, we get another prime number with digits reversed. How many such numbers are possible ?

If n^2+2n-8 is a prime number where n in n , then n is a. also a prime number b. relatively prime to 10 c. relatively prime to 6 d. a composite number

How many three digit numbers are there in which all the digits are odd?