What is the annual nominal interest rate of a $\$500$ loan payable in two weeks at $\$675$? What is the effective annual interest rate? What is the annual nominal interest rate of a $\$500$ loan payable in two weeks at $\$675$? What is the effective annual interest rate? Assume it compounds $26$ times in a year, how much money would be owed at the end of the year? I think if I could determine the nominal interest rate the rest of the problem would flow well from there. I'm aware that it's a 35% interest rate compounded every two weeks but I'm unaware of how translate this to an annual nominal rate.

Hint.

Since $675/500 = 1.35$ you've correctly calculated the $35\%$ rate for two weeks. After two more weeks you'd owe $$ 1.35\times 1.35 \times \$500 = 1.35^2 \times \$500 = 1.8225 \times \$500 = \$911.25 $$ for a four week interest rate of $82.25\%$.

Can you finish?

Don't be surprised when the amount owed and annual interest rate seem unimaginably large.