Which is the right answer?

Andy has $310 in his account. each week, w, he withdraws $30 for his expenses. which expression could be used if he wanted to find out how much money he had left after 8 weeks?

Gigi earned $65 for 5 hours of gardening. she earned $90 for 9 hours of office work. which statement correctly compares gigi’s earning per hour for gardening and office work? she earned $3 more per hour for office work than for gardening. she earned $4 more per hour for office work than for gardening. she earned $3 more per hour for gardening than for office work. she earned $4 more per hour for gardening than for office work.

Whats four fifths to the first power