The correct answer is: $7.874\text{ in}$ (approximately $7.87\text{ in}$)
Explanation
We use the exact conversion $1\text{ in} = 2.54\text{ cm}$ to convert centimeters to inches.
Steps:
- Conversion factor: $1\text{ in} = 2.54\text{ cm}$
- Set up the conversion: $$20\text{ cm}\times\frac{1\text{ in}}{2.54\text{ cm}}=\frac{20}{2.54}\text{ in}$$
- Calculate: $$\frac{20}{2.54}\approx7.874015748\text{ in}\approx7.87\text{ in}$$
Therefore, 20 cm is about $7.87\text{ in}$ (roughly $7\frac{7}{8}\text{ in}$).