Question

Which is the greatest length: 5 miles, 25,800 feet, or 10,600 yards? Keep in mind that 1 mile = 1,760 yards, and 3 feet = 1 yard.

Answer 1

since the three quantities are in different units, they're hard to compare. so let's convert them all to the same unit (I'll use feet, but really you could pick any unit as long as you're consistent)

since 1 mile = 5280 feet ---> 5 miles is simply 5 * 5280 feet
since 1 yard = 3 feet ---> 10,600 yards = how many feet?

once you have them all in feet, whichever quantity is the greatest should be clear