What is 582 rounded to the nearest ten

Given this information, which expression must represent the value of b?

Afrequency table of grades has five classes (a, b, c, d, f) with frequencies of 3, 13, 14, 5, and 3 respectively. using percentages, what are the relative frequencies of the five classes?

Question 14 (1 point) larry deposits $15 a week into a savings account. his balance in his savings account grows by a constant percent rate.