A firm offers terms of $1/25,$ net $40.$

What effective annual interest rate does the firm earn when a customer does not take the discount?

Note: Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$

What effective annual interest rate does the firm earn if the discount is changed to $2$ percent?

Note: Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$

What effective annual interest rate does the firm earn if the credit period is increased to $60$ days?

Note: Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$

What effective annual interest rate does the firm earn if the discount period is increased to $30$ days?

Note: Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$