Question

Which among the following is a four digit prime number using the digits $1,7,0,9$?

• A. $1790$
• B. $1709$
• C. $9710$
• D. $7910$

Answer 1

Answer: (B)

$1709$

A prime number is a number which is only divisible by itself and $1$.

(a) $1790$ is divisible by $2$, so it is not a four digit prime number.

(b) $1709$ is only divisible by itself, so it is a four digit prime number.

(c) $9710$ is divisible by $2$, so it is not a four digit prime number.

(d) $7910$ is divisible by $2$, so it is not a four digit prime number.

Hence, $1709$ is a four digit prime number using the digits $1,7,0,9$.