How long will it take two copiers working together to copy a dissertaion if one can finish in 8 min and another can finish in 14?

To find the time it takes for the two copiers to work together, first determine their individual rates: the first copier can complete the job in 8 minutes, so its rate is 1/8 of the job per minute, while the second copier's rate is 1/14. Adding these rates together gives (1/8 + 1/14). Finding a common denominator (56), we get (7/56 + 4/56) = 11/56 of the job per minute. Therefore, the time to complete the dissertation together is the reciprocal of this rate, which is 56/11 minutes, or approximately 5.09 minutes.