Question

Sam opened a money-market account that pays 2% simple interest. He started the account with $7,000 and made no further deposits. When he closed the account, he had earned $420 in interest. How long did he keep his account open?

Answer 1

I = prt
420 = 7000 x .02 x t
420 = 140 x t
420/140 = 140 x t /140
t = 3 years