Question

Henry Devine bought a new dishwasher for $320. He paid $20 down and made 10 monthly payments of $34. What actual yearly interest rate did Henry pay? 

    A. 68.75 B. 14.55 C. 34.38
D. 29.09

The answer is B?

Answer 1

   Lily Quinn makes $12.50 and hour. She works four hours on Monday, six hours on Tuesday, nine hours on Wednesday, three hours on Thursday, and seven hours on Friday. What is her gross pay? 

    A. $462.50 B. $325.50 C. $362.50 D. $420.50

The answer is C?

Answer 2

Both look good to me, but not sure about #1.

Answer 3

#1.
present value of loan = 320-20=300
payment = 34
n = 10
let the monthly rate be i

34( 1 - (1+i)^-10)/i = 300

There is no simple algebraic method to solve this type of equation.
One method is interpolation, or if you know calculus, you could use Newton's Method.
I will run it through Wolfram and see what they say:
http://www.wolframalpha.com/input/?i=solve+34%28+1+-+%281%2Bx%29%5E-10%29%2Fx+%3D+300
and using the only logical possible answer of
i = .0234293
we have a monthly rate of .0234
or an annual rate of (.0234..)
(12)
<b>which is appr 28.1% per annum compounded monthly</b>

The closest of your choices is D

check:
34(1 - 1.0234^-10)/.0234 = 300.00455 , not bad