Lenny put 20 animal stickers in 4 equal rows in her sticker book. she put 24 flower stickers i n 6 equal rows. how many more animal stickers than flower stickers are in each row?

Sam opened a money-market account that pays 3% 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?