In this task you will be given an answer to a question. You need to generate a question. The answer given should be a correct answer for the generated question.
Q: The acre is a unit of land area used in the imperial and US customary systems. It is defined as the area of 1 chain by 1 furlong (66 by 660 feet), which is exactly equal to ​ ⁄ of a square mile, 43,560 square feet, approximately 4,047 m, or about 40% of a hectare.
A: 
how much is 100 acres of land in miles