What is one hundred sixty of these equal one square mile?

4 square acres

is the closest answer

We have to find the area which multiplied by 160 gives 1 square mile.

We know that : 1 square mile = 0.3867 sq km.

So it is not from the metric system.

The acre is exactly 1/640 of a square mile. 1/4 of the square mile is 160 acres.

1 sq mile = 640 acres

1 sq mile = 160 * 4 acres

Answer: 4 acres.