(1) The interest of a loan product A is 4%/ month. If you borrow 3000 yuan and pay it back in one year, the interest is 3000* 12*4%= 1440 yuan.

(2) The interest of a loan product B is monthly, the loan amount is1000-8,000 yuan, and the loan term is 6- 18 months. If the loan is 3,000 yuan, the loan term is one year, and the interest is 3,000 *12 * yuan.

(3) If the monthly interest of a loan product C is 3,000 yuan and the loan term is one year, the interest is 3,000 *12 * yuan.

Note: In addition to interest, many lending institutions will charge some other fees, so you must know clearly before lending.