Interest is computerd on the principal and also on the accumulated past interest​

With number 11 ( show how you got the answer)

The water company charges a residential customer $41 for the first 3,000 gallons of water used and $1 for every 200 gallons used over 3000 gallons. if the water bill was $58 how many gallons of water were usedanswersa 3400 gallonsb 6000 gallonsc 6400 gallons d 7000 gallons

Find the value of x to the nearest tenth. a. 4.5 b. 5.4 c. 6.3 d. 7.2