Ana is using a photocopier to make 315 copies of a poster. It takes 3 minutes to print the first 63 posters. If the photocopier continues to print at the same rate, how many more minutes will it take to complete the job?

Answer 1

If it takes 3 minutes to print 63 posters, then Ana can print 63/3 = <<63/3=21>>21 posters per minute.
To make 315 copies, Ana will need an additional 315 - 63 = <<315-63=252>>252 copies.
At a rate of 21 posters per minute, it will take an additional 252/21 = <<252/21=12>>12 minutes to complete the job. Answer: \boxed{12}.