Help math almost done thank pleas

Aboat costs 19200 and decreases in value by 12% per year. how much will it cost in 5 years

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?

Which expression is rational? 6. , square root two, square root 14, square root 49