A real number is any number that is rational, including integers and natural numbers. A rational number is any number that can be written as a ratio or isn't a square root of a number. An integer is any whole number (not including fractions) that exists, negative or positive. A whole number is the same as an integer except it only includes positive numbers. Since a set of whole numbers wouldn't be able to include any negative numbers, your answer would be your fourth option. Hope this helped you out! :-)
Well, to calculate that, you have to multiply the number of bats by the "number" version of 31.5 %, which once you multiply them together, it comes out to be about 149 (148.995)
