Answer:
Studying every single instance of a thing is impractical or too expensive
Step-by-step explanation:
With sampling we a have a lot of data without much effort.
C = 2 pi r
but c = 15
15 = 2 pi r
15 = 2 * (22/7) * r
r = (15*7) / 2 / 22
r = 2.386
Each time you fold a paper it will double the amount of parts. When you think about it, it's just multiplying by 2 a bunch of times.
One fold is 2 times 1, which is 2.
The second fold is 2 times 2, which is 4.
The third fold is 4 times 2, which is 8.
Using this process, we can simplify that into exponents. If the amount of times you fold is x and the parts double for each fold, then the amount of parts can be represented by:

So if the amount of parts is given and we need the amount of folds, just keep doubling until you get to 64. The amount of times you doubled is the number of times Sylvie folded.
Later you will learn that the opposite of an exponent is a logarithm, which would look like this:

But don't worry about that yet.
The answer is 84 because of process priority
Let the distance be x miles
Time = Distance / speed
Time taken by Mike to go to his friend's house = x / 40 hours
Time taken by him to return = x / 45 hours
Total time = x / 40 + x / 45 = 4 hours
= 9x + 8x = 1440 miles
17x = 1440
= x = 1440 ÷ 7
= x = 84.706
Time taken to return home = 84.706 /45= 1.882 hours .
Therefore , Mike took 1.882 hours to reach home .