Alan deposited 300$ into a savings account. At the end of the year, the amount of money in the account had increased to $336. At the end of the second year, he had 420

During the first year he had an annual interest of 12%, and in the second year of 25%

Step-by-step explanation:

To calculate the interest of the first year:

(Initial capital of the first year / final capital of the first year) - 1 = interest of the first year

(300/336) - 1 = 0.12 = 12%

To calculate the interest of the second year:

(Initial capital of the secondyear / final capital of the second year) - 1 = interest of the second year

(336/420) - 1 = 0.25 = 25%