Why is there sometimes a remainder in division

Labc is reflected across x = 1 and y = -3. what are the coordinates of the reflection image of a after both reflections?

Simplify (1/2)4th power a. (1/16) b.(1/8) c.(1/4)

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?