Question

Write two pairs of twin primes between $20$and $50$.

• A. $16$ and $26$, $19$and $29$
• B. $29$ and $31$, $41$ and $43$
• C. $11$ and $21$, $61$ and $71$
• D. $15$ and $17$, $37$ and $39$

Answer 1

The correct option is B

$29$ and $31$, $41$ and $43$

Twin primes is pairs of two prime numbers such that the difference between the two prime numbers is $2$.

Explanation of the correct answer.

Option B:

$29$ and $31$, $41$ and $43$

Here, $29$ and $31$, are prime with the difference of two between them.

Also $41$ and $43$ are also prime with the difference of two between them.

Explanation for the incorrect answer.

Option A:

$16$ and $26$, $19$and $29$

Since none of $16$ and $26$ are prime numbers. So, no point in them being twin prime.

Also, difference between $19$and $29$ is not $2$. Even if it is prime.

therefore they are not a twin prime number between $20$and $50$

Option C:

$11$ and $21$, $61$ and $71$

since, $61$and $71$ don't lie between $20$and $50$.

Thus they are not a twin prime number between $20$and $50$

Option D:

$15$ and $17$, $37$ and $39$

Since, among $15$ and $17$, $15$ is not a prime number thus they are not a twin prime numbers

And among $37$ and $39$, $39$ is not a prime number.

Hence, only option B is correct.