Which of the following numbers are rational? Also, identify the irrational numbers.
9990

Answer

To determine whether the number 9990 is rational or irrational, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Rational and Irrational Numbers**:
- A rational number is defined as any number that can be expressed in the form of \( \frac{p}{q} \), where \( p \) and \( q \) are integers and \( q \neq 0 \).
- An irrational number cannot be expressed in this form.

2. **Analyzing the Given Number**:
- The number given is 9990.

3. **Expressing 9990 in the Form of \( \frac{p}{q} \)**:
- We can express 9990 as \( \frac{9990}{1} \).
- Here, \( p = 9990 \) and \( q = 1 \).

4. **Checking the Conditions**:
- Both \( p \) (9990) and \( q \) (1) are integers.
- \( q \) is not equal to 0.

5. **Conclusion**:
- Since 9990 can be expressed in the form \( \frac{p}{q} \) where \( p \) and \( q \) are integers and \( q \neq 0 \), it is a rational number.

### Final Answer:
- **Rational Number**: 9990
- **Irrational Numbers**: None (since 9990 is the only number provided and it is rational).