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A prime number contains the digit X at unit’s place. How many such digits of X are possible?

3
4
5
6

Correct Answer: 6

Explanation:

For prime no units place cannot be occupied by even number except for 2

Thus no of digits occupying unit digit of prime numbers = 6 (1,2,3,5,7,9)

Example 2,3,5,7,11,19 in itself are prime numbers

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