Acraft store has 540 packs of yarn on sale. the store sells 65% of the packs by the end of the day

Molly shared a spool of ribbon with 12 people. each person received 3 feet of ribbon. which equation can she use to find r, the number of feet of ribbon that her spool originally had?

Compound inequalities. , i’m being timed

Find the sum of the given arithmetic series. 24 + 17 + 10 + 3 + + (–39)