Iwill give the brainiest for someone who will do the can me with 13, 14 and 15

If the sales price of a dvd is $20 and the markup is 34%, what is the cost of the dvd?

Your friend uses c=50p to find the total cost, c, for the people, p, entering a local amusement park is the cost of admission proportional to the amount of people entering the amusement park? explain.

60 musicians applied for a job at a music school. 14 of the musicians play both guitar and drums, 28 play drums, 18 play the guitar. what is the probability that the applicant who gets the job plays drums or guitar?