Twin Prime Numbers

Q.

If HCF of two numbers is $1$, the two numbers are called relatively ________ or ________.

Q.

Which is the number that is neither prime nor composite?

Q. Write 5 pairs of twin prime numbers from 1 to 50.

Q.

H.C.F of 17, 34 and 51 is:

1. 34

2. 1

3. 51

4. 17

Q.

Numbers having factors 1 and itself are called ______ numbers.

1. natural

2. prime

3. composite

4. integer

Q.

What is the smallest pair of twin prime?

Q.

What is the greatest common divisor of 18 and 45?

1. 45

2. 15

3. 9

4. 3

Q.

Which is a pair of twin prime numbers?

1. 10, 11
2. 11, 13
3. 24, 28
4. 22, 24

Q. Find the greatest number that divides 2, 3 & 6 exactly.

1. 3
2. 2
3. 1
4. 5

Q. The two consecutive prime numbers with difference $2$ are called

1. co-primes
2. twin primes
3. composite
4. none of these

Q. Which of the following pairs are twin primes?

1. $(19,21)$
2. $(29,31)$
3. $(39,41)$
4. $(49,51)$

Q.

$1$ is not a prime number. Is it a composite number?

Q.

$1$ is neither __________nor__________

Q.

Write the HCF of : two co-prime numbers.

Q.

The HCF of two prime numbers is ___________

Q.

Write the HCF of : two distinct prime numbers

Q. Which of the following are twin primes?

1. 21, 23
2. 13, 15
3. 5, 11
4. 11, 13

Q. The HCF of two or more prime numbers is always __________

Q. What are twin-primes ?

Q. If 2009 = $p^a.q^b$ where p and q are prime numbers then find the value of p + q

1. 3
2. 48
3. 2009
4. 51

Q.

State the following as prime or composite: $31$

Q. Which of the following are twin primes?

1. $(5,7)$
2. $(3,5)$
3. $(2,3)$
4. $(11,13)$

Q. Twin primes consist of

1. composite numbers
2. prime numbers
3. even numbers
4. none of these

Q.

Find out a number which is neither prime nor composite.

Q. Which one of these is neither a prime number nor a composite number?

1. 4
2. 2
3. 7
4. 1

Q. An example for twin primes is

1. $5,11$
2. $11,17$
3. $3,5$
4. $3,7$