Prime Time

Why is prime factorization important in mathematics?

1. It changes composite numbers into prime numbers.
2. It helps find HCF, LCM, and simplifies mathematical calculations.
3. It increases the value of numbers.
4. It is used only in geometry.

The prime factors of 30 are:

1. 2 × 3 × 5
2. 5 × 6
3. 10 × 3
4. 15 × 2

Which number is divisible by 9?

1. 52
2. 63
3. 71
4. 82

Which pair consists of two co-prime numbers?

1. 8 and 12
2. 9 and 27
3. 14 and 21
4. 8 and 15

Which number has only one factor?

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

The LCM of 3 and 5 is:

1. 8
2. 10
3. 15
4. 30

The HCF of 12 and 18 is:

1. 2
2. 3
3. 6
4. 9

Which of the following numbers is not prime?

1. 29
2. 37
3. 41
4. 51

Which number is a multiple of both 4 and 6?

1. 12
2. 16
3. 18
4. 20

Prime factorization of 36 is:

1. 2 × 18
2. 2 × 2 × 3 × 3
3. 6 × 6
4. 4 × 9

Which of the following is divisible by both 2 and 3?

1. 18
2. 25
3. 35
4. 49

Which of the following numbers has exactly three factors?

1. 4
2. 5
3. 6
4. 8