Not sure how this is done but i have to give my answer to 1 decimal places.

Ateacher has $80 to buy workbooks. each work book cost $3. if she buys as many workbooks as possible, how much money does she have leftover? a) $2 b) $4 c) $6 d) $8

The cost of using a service is $0.25 per min. what equation correctly represents the total cost c, in dollars, for d days of use?

Abox holds 500 paperclips. after a week on the teacher's desk 239 paperclips remained. how many paperclips were used?