If E = {even integers}, then insert the appropriate symbol `in` or `cancel(in)` in the blanks :
13 . . . . . E

Answer

To solve the problem, we need to determine whether the number 13 belongs to the set of even integers (E).

### Step-by-Step Solution:

1. **Understand the Set E**:
- The set E is defined as the set of even integers. Even integers are numbers that can be divided by 2 without leaving a remainder. Examples include -4, -2, 0, 2, 4, 6, etc.

2. **Identify the Number in Question**:
- The number we are examining is 13.

3. **Determine if 13 is Even**:
- To check if 13 is an even integer, we divide it by 2.
- \( 13 \div 2 = 6.5 \)
- Since 6.5 is not an integer, this means that 13 is not divisible by 2 without a remainder.

4. **Conclusion**:
- Since 13 is not an even number, it does not belong to the set E of even integers.
- Therefore, we use the symbol that indicates it does not belong, which is `cancel(in)`.

5. **Final Answer**:
- The correct symbol to insert is: **13 cancel(in) E**.