On December $31,2020,$ Waterway Bank enters into a debt restructuring agreement with Barkley Company, which is now experiencing financial trouble. The bank agrees to restructure a $12\%,$ issued at par, $$3,700,000$ note receivable by the following modifications:

Reducing the principal obligation from $$3,700,000$ to $$2,960,000.$

Extending the maturity date from December $31,2020,$ to January $1,2024.$

Reducing the interest rate from $12\%$ to $10\%.$

Barkley pays interest at the end of each year. On January $1,2024,$ Barkley Company pays $$2,960,000$ in cash to Waterway Bank. Answer the following questions related fo Waterway Bank $($creditor$).$

$($a$)$

What interest rate should Waterway Bank use to calculate the loss on the debt restructuring? $($Round answer to $0$ decimal places, e$.$g$.18\%.)$