Joannie lent $200 to her sister. four years later, her sister repaid her in full with $228. what simple annual interest rate did joannie's sister pay? a. 3.0% b. 3.5% c. 4.0% d. 4.5%

Ok, so lets convert all the percents into decimals to help us solve this problem

A 3.0%= 0.03

B 3.5%= 0.035

C 4.0%= 0.04

D 4.5%= 0.045

Now, we can multiply $200 by all the decimals we just converted to see which one will add up to $208

200*0.03= 6200+6=206 (this is not equal to 208 so it's not A)

200*0.035=7200+7= 207 (Still does not equal 208, so it's not B)

200*0.04= 8200+8=208 C is your answer

something that characterises a right triangle is the fact that we may use pythagoras' theorem to find any one of its sides given that we have the length of the other two sides. here, we have the length of the hypotenuse, √(87) yd, and one other side, √(23) yd, thus we can easily find the length of the remaining side using pythagoras' theorem as defined below:

c^2 = a^2 + b^2, where c is the length of the hypotenuse, and a and b are the lengths of the other two sides.

thus, given that c = √(87) and a = √(23), we may substitute these into the formula we defined above to get:

c^2 = a^2 + b^2

(√87)^2 = (√23)^2 + b^2 (substitute c = √87 and a = √23 into the equation)

87 = 23 + b^2 (evaluate (√87)^2 = 87 and (√23)^2 = 23 - remember that the square root of a number, squared will equal that very same number)

64 = b^2 (subtract 23 from both sides)

√64 = b (take the square root of both sides)

8 = b (evaluate √64 = 8)

therefor, the length of the unknown leg in the right triangle is 8 yd (first answer).