Prime Factorization

Q.

Three bells toll together at intervals of 9, 12 and 15 minutes. If they start tolling together, after what time will they toll next?

1. 1 hour

2. 2 hours

3. 3 hours

4. 4 hours

Q. Find the sum of the prime factors of 1729.

Q.

Write all prime numbers less than $30$.

Q.

The sum of all positive divisors of $242$ except $1$ and itself is

1. $156$

2. $242$

3. $342$

4. $399$

Q.

Question 6

Find all the prime factors of 1729 and arrange them in ascending order. Now state the relation, if any, between, two consecutive prime numbers.

Q. what is vampire number?

Q. Find the prime factorization of 2048.

Q.

Express 28 as product of its prime factors.

1. $2\times 4\times 7$

2. $2\times 14$

3. $2\times 2\times 7$

4. $2\times 3\times 4\times 7$

Q. The prime factorization of 999 is:

1. $99\times 11$
2. $3^3\times 37$
3. $9\times 111$
4. $3^2\times 37$

Q. Find all the natural numbers which are less than 24 and also coprime to it.

Q. Express the number as product of its prime factors:

1. $4\times 17\times 13\times 7$
2. $5\times 11\times 13\times 7$
3. $7\times 11\times 19\times 29$
4. $5\times 13\times 19\times 29$

Q. The largest prime factor of 24 is .

1. 8
2. 7
3. 5
4. 3

Q.

Find by Prime factorization LCM of

$112,168and228$

Q.

The Prime Factorization of 625 is ___.

1. 72 = 2×2×2×3×3×3

2. 105=3×5×7

3. 625=5×5×5×5×5

4. 162= 2×3×3×3×3×7

Q.

Express the following as a product of prime numbers .

$12$

Q.

The prime factors of a number is given as 3 × 3 × 11 × 101. Which of the following is correct about the number?

1. It is an even number.

2. It is the smallest 4 digit odd number.

3. The number is 10000.

4. It is the greatest 4 digit number.

Q. The sum of all the prime factors of $m$ is 9. Find the number $m$.

1. 15
2. 18
3. 28
4. 12

Q. What is the sum of only even prime number and smallest prime number?

1. 0
2. 3
3. 2
4. 4

Q.

In which table does $39$ comes?

Q. Compute the LCM of 30 and 12 using prime factor method.

Q.

Write the smallest 4 digit number and express it in terms of prime factors .

Q.

The sum of all the prime factors of $m$ is 9. Find the number $m$.

1. 28

2. 15

3. 20

4. 63

Q. Find the sum of the prime factors of 4620.

Q. Which of the following represents the prime factorisation of 60?

1. 2 x 2 x 5

2. 2 x 2 x 3 x 5

3. 2 x 2 x 3

4. 2 x 2 x 3 x 5 x 5

Q. Express the following number as a product of its prime factors:

1. $11\times 19\times 23$
2. $17\times 19\times 23$
3. $17\times 19\times 29$
4. $17\times 23\times 23$

Q. (i) Find the H.C.F. of 90 and 162.
(ii) Find the L.C.M. of 90 and 162.
(iii) What is the product of HCF and LCM of 90 and 162?

Q. The sum of all the prime factors of $m$ is 9. Find the number $m$.

1. 12
2. 15
3. 28
4. 18

Q.

Choose the correct option.

1. 625=5×5×5×5×5

2. 105=3×5×7

3. 72 = 2×2×2×3×3×3

4. 162= 2×3×3×3×3×7

Q. Which of the following are the common factors of 6 and 10?

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

Q.

Express following number as the sum of three prime number - :

$10=.........+..........+..........$ .