Which of the following in the best estimate for 78x62?

(1)4200
(2)4800
(3)4900
(4)5600

Add the fractions, and simply the result to lowest terms. 2/3 + 2/7= ?

If you can solve all of these i will give ! - 4% of 190 - 4% of 162.5 - 4% of 140 - a 4% increase from 155.1 - a 4% increase from 159.8

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?