Heather worked on 4 command cards in 140 minutes. At the same rate, how many cards can she complete in 315 minutes?

Darcy deposited $390 into a savings account. as long as the account balance remains at or above $150, she does not have to pay a service fee for the account. for how many months can she withdraw $40 a month without having to pay service fees? a) 3 b) 5 c) 6 d) 9