POW #5

POW #5

Choose between one of the following problems, or do all three!

Prime Number: A prime number is a positive integer that has exactly two positive integer factors, 1 and itself. For example, if we list the factors of 28, we have 1, 2, 4, 7, 14, and 28. That's six factors. If we list the factors of 29, we only have 1 and 29. That's two factors. So we say that 29 is a prime number, but 28 isn't.

If a number is NOT prime, it is called "composite."

PRIME Question
What is the greatest prime number that can be represented as both the sum of 2 prime numbers and as the difference of 2 prime numbers?

OR

Ruby's Numbers
The sum of Ruby's numbers is 31. The square root of the different of the two numbers is 5. What are Ruby's two numbers?


OR

Walking the Earth
For this problem, assume that the earth is a perfect sphere. A person who is 2 meters tall is walking around the earth at the equator. How much further will the person's head travel compared with her feet? Round your answer to the nearest tenth of a meter.