I don't know about the circle, but from the way it looks, you can use pythagorean theorem (A^2+B^2=C^2). angle E would be the Right Angle making 65=C or in other words, the hypotenuse, with 60 and Line ED being the legs (it doesn't matter which is A and which is B) leaving the equation
60^2+B^2=65^2 and solve from there. (if you need help solving, leave a comment and i will walk you through it in the comments)

We are trying to isolate
. Subtract
from both sides. 
Find the square root of both sides. 
<em>Note: I've attached a graph of
.</em>
Answer:
Part 1) 
Part 2) 
Part 3) 
Part 4) 
Part 5) 
Step-by-step explanation:
Part 1) Write as a percent 0.00675
we know that
To write a number as a percent, multiply the number by 100
so

Part 2) Write as a percent 4 3/4
Convert mixed number to an improper fraction

we know that
To write a fraction as a percent, multiply the fraction by 100

Part 3) Write as a percent 2/25
we know that
To write a fraction as a percent, multiply the fraction by 100

Part 4) write as a fraction 335%
we know that

Simplify
Divide by 5 both numerator and denominator

Part 5) Write as a decimal 265%
we know that

It's a big alphabet, why confuse us with N and n?
Anyway, this one is a bit easier than it looks. We're going to look at it mod 11, meaning we're only interested in the remainders when we divide by 11. The nice thing about multiplication and addition is if we're going to take the remainder at the end, we can also take the remainders at the beginning and along the way and get the same answer, with smaller numbers.
That all sounds very complicated. It's easier explained.
100 =9*11 +1 so has remainder 1 when divided by 11. So if we multiply by 100 that's not going to change the remainder when we divided by 11; it's like multiplying by 1.
So 100, 100^2, 100^3, etc all have remainder 1 when divided by 11. So we need to add up 11 of them to get a number that's divisible by 11.
Answer: 11