In which of the following, lengths have been arranged in decreasing order?

Options

A. 8500 mm, 800 cm 8 mm, 80 dm 8 cm, 8 m
B. 80 dm 8 cm, 8500 mm, 8 m, 800 cm, 8 mm
C. 8 m, 80 dm 8 cm, 8500 mm, 800 cm, 8 mm
D. 8500 mm, 80 dm, & cm 800 cm 8 mm, 8 m

Answer

To determine which of the following lengths have been arranged in decreasing order, we need to convert all the given lengths into the same unit. Let's convert everything into millimeters (mm) for consistency.

### Given Options:
1. **Option A:** 85 mm, 100 mm, 800 cm, 8 mm
2. **Option B:** 80 dm, 8 cm, 8 m
3. **Option C:** 800 cm, 8 mm
4. **Option D:** 8500 mm, 8800 mm, 8000 mm

### Step-by-Step Solution:

**Step 1: Convert all lengths to millimeters.**

1. **Option A:**
- 85 mm = 85 mm
- 100 mm = 100 mm
- 800 cm = 800 × 10 mm = 8000 mm
- 8 mm = 8 mm
- **Total in mm:** 85 mm, 100 mm, 8000 mm, 8 mm

2. **Option B:**
- 80 dm = 80 × 100 mm = 8000 mm
- 8 cm = 8 × 10 mm = 80 mm
- 8 m = 8 × 1000 mm = 8000 mm
- **Total in mm:** 8000 mm, 80 mm, 8000 mm

3. **Option C:**
- 800 cm = 800 × 10 mm = 8000 mm
- 8 mm = 8 mm
- **Total in mm:** 8000 mm, 8 mm

4. **Option D:**
- 8500 mm = 8500 mm
- 8800 mm = 8800 mm
- 8000 mm = 8000 mm
- **Total in mm:** 8500 mm, 8800 mm, 8000 mm

**Step 2: Arrange the lengths in decreasing order for each option.**

1. **Option A:** 8000 mm, 100 mm, 85 mm, 8 mm → Not in decreasing order.
2. **Option B:** 8000 mm, 8000 mm, 80 mm → Not in decreasing order.
3. **Option C:** 8000 mm, 8 mm → Not in decreasing order.
4. **Option D:** 8800 mm, 8500 mm, 8000 mm → This is in decreasing order.

### Conclusion:
The correct option where the lengths are arranged in decreasing order is **Option D: 8800 mm, 8500 mm, 8000 mm.**

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