If a pheretima has 80 segments and intestine starts from 15th segments, in how many segments does the intestine extended? 

Options

A. a. 60
B. b. 50
C. c. 65
D. d. 70

Answer

To solve the problem, we need to determine how many segments the intestine of the pheretima (earthworm) extends through, given that it starts from the 15th segment and the total number of segments is 80.

### Step-by-Step Solution:

1. **Identify the starting segment of the intestine**: The intestine starts from the 15th segment.

**Hint**: Look for the information that tells you where the intestine begins.

2. **Identify the total number of segments**: The total number of segments in the pheretima is given as 80 segments.

**Hint**: This is the total length of the organism, which will help you determine the extent of the intestine.

3. **Calculate the ending segment of the intestine**: Since the intestine runs from the 15th segment to the last segment (80th segment), we can find the number of segments it extends through by calculating:
- Ending segment = Total segments - Starting segment + 1
- Ending segment = 80 - 15 + 1 = 66

**Hint**: Remember to include the starting segment in your count when calculating the total length.

4. **Determine the number of segments the intestine extends through**: The intestine extends from the 15th segment to the 80th segment, which means it covers:
- Total segments covered = Ending segment - Starting segment + 1
- Total segments covered = 80 - 15 + 1 = 66

**Hint**: Ensure you are counting all segments from the starting point to the endpoint.

5. **Final Answer**: The intestine extends through 66 segments.

**Hint**: Double-check your calculations to ensure accuracy.

### Conclusion:
The intestine of the pheretima extends through 66 segments, starting from the 15th segment to the 80th segment.