I= prt
i = simple interest, p = principal, r = rate, t = time.
you want to study at the hogwarts school of witchcraft and wizardry after five years. you need 800 pieces of muggle-money to study there. you decide to deposit some pieces in the bank at an annual interest rate of %12.

The amount  we need to invest is 500 muggle money.

Step-by-step explanation:

Amount needle to study at Hogwarts = A = 800 muggle money

Principle amount that we need to invest = P

Duration of investment = T = 5 years

Rate if simple interest = R = 12%

Simple interest =  S.I

A = S.I + P

P =

The amount  we need to invest is 500 muggle money.

the input value is the number of times you fold it. the input value is also known as the x-value. 

the output value is its thickness. the output value is the y-value.

when you don't fold it all, the thickness will remain the same, which is 1. the ordered pair would be (0,1).

when you fold it once, the thickness will double from 1 to  2. the ordered pair would be (1,2).

when you fold it a second time, the thickness will double from 2 to  4. the ordered pair would be (2,4).

fold it one more time, and the thickness will be 8. the ordered pair is (3,8)

fold it the fourth time, and the thickness doubles. 8 x 2 = 16. the ordered pair is (4,16)

fold it the fifth time, and the thickness goes from 16 to 32. the ordered pair is (5,32)

the ordered pairs would be:

(0,1)

(1,2)

(2,4)

(3,8)

(4,16)

(5,32)

(6,64)

(7,128)

and so on : p

the question asks for 6 ordered pairs, so i bolded the first six.

now, the equation for this would be 

if we graph that, and we do the vertical line test, then we know this is a function.

it is a function because each x-value has a different y-value. there are no y-values that have the same x-values.

i have attached the graph of that line.

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step-by-step explanation:

it is a. 4.2 because 7.6-3.4 gets the remaining length of 4.2. i might be wrong but i am pretty sure this is the answer.