## 1. Every natural number is:

### Answer:

### Explanation:

Natural numbers are a subset of real numbers. Thus, every natural number is a real number.

## 2. Which of the following is an irrational number?

### Answer:

### Explanation:

√2 cannot be expressed as a fraction of two integers, making it an irrational number.

## 3. Which of the following is NOT a property of real numbers?

### Answer:

### Explanation:

Multiplicative Inversion is not a property; it's a concept where each number has an inverse such that their product is 1.

## 4. The decimal expansion of a rational number:

### Answer:

### Explanation:

The decimal expansion of a rational number either terminates or becomes recurring.

## 5. Which number is NOT rational?

### Answer:

### Explanation:

√5 does not have an exact decimal representation and cannot be expressed as a quotient of two integers.

## 6. The smallest prime number is:

### Answer:

### Explanation:

2 is the smallest and only even prime number.

## 7. The HCF of two prime numbers is:

### Answer:

### Explanation:

Two distinct prime numbers do not have any common factors other than 1.

## 8. If a and b are real numbers, then a × b is:

### Answer:

### Explanation:

The product of two real numbers is always a real number.

## 9. An example of a non-terminating, non-recurring decimal is:

### Answer:

### Explanation:

3.141592… represents the irrational number π, which is non-terminating and non-recurring.

## 10. Which of the following is an example of a composite number?

### Answer:

### Explanation:

9 can be divided by 1, 3, and 9. Hence, it's a composite number.

## 11. Which of the following numbers lies between 0 and 1?

### Answer:

### Explanation:

√1/2 is equal to √0.5, which is between 0 and 1.

## 12. The value of (-1) × (-1) is:

### Answer:

### Explanation:

Negative multiplied by negative gives a positive number.

## 13. An integer that is not prime is called:

### Answer:

### Explanation:

A composite number has more than two distinct positive divisors.

## 14. The number 0 is:

### Answer:

### Explanation:

0 can be expressed as 0/1, making it a rational number.

## 15. Which of the following is an integer?

### Answer:

### Explanation:

√4 is equal to 2, which is an integer.

## 16. The LCM of 1 and any integer 'n' is:

### Answer:

### Explanation:

1 is a factor of every integer, so the LCM of 1 and any integer 'n' is 'n'.

## 17. Which of the following numbers is rational?

### Answer:

### Explanation:

0.75 can be expressed as 3/4, which is a ratio of two integers.

## 18. If x is an integer and y is a fraction, then x+y is:

### Answer:

### Explanation:

The sum of an integer and a fraction is a real number.

## 19. The product of two irrational numbers:

### Answer:

### Explanation:

For instance, the product of √2 and √2 is 2, which is rational.

## 20. The sum of two rational numbers is always:

### Answer:

### Explanation:

The sum of two rational numbers is always rational.