Question

If $a,b$ are two single digit prime numbers such that their sum is also prime number, then their product can be

• A. $8$
• B. $10$
• C. $12$
• D. $16$

Answer 1

The correct option is B $10$

Since, $a,b$ are two single digit prime numbers.
So, $a,b$ can be $2,3,5,7$
Given: $a+b$ is also prime, then it is must be odd number.
So, either $a$ or $b$ must be even.
Let $a=2$
So, $b$ can be $3,5$
So, possible pairs are $(2,3)$ and $(2,5)$
Hence, product $ab=6$ or $10$