The product of a non-zero rational number and an irrational number is irrational. Therefore C is the answer. A, B, and D are all properties of rational numbers. Irrational numbers are ones that can not be written as a ratio, or fraction, using whole numbers. They are non-repeating, non-terminating numbers. Example would be pi.
935 miles. This is because it takes 1 minute to travel 9.16667 miles. There is 102 minutes in 1 hour and 42 minutes, so you take 9.16667 * 102, this gets you 935 miles. Hope this helps.