A loan of 5000 can be repaid by payments of 117.38 at the end of each month for n years (12n payments), starting one month after the loan is made. At the same rate of interest, 12n monthly payments of 113.40 each accumulate to 10000 one month after the final payment. Find the equivalent effective annual rate of interest.

The wording of the question is a little confusing to me. I attempted the question, and let x = 1+i at some point, but nothing seemed to work out. Any help would be appreciated