Help with my mathtthhh

An advertising firm has an old computer that can prepare a whole mailing in 6 hours. with the of newer model the job is complete in 2 hours. how long would it take the newer model to do the job alone?

Aresearch group wants to find the opinions’ of city residents on the construction of a new downtown parking garage. what is the population of the survey downtown shoppers downtown visitors downtown workers city residents

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