Master Plumber A can finish a job in 8 hours while Master Plumber B takes 10 hours. How many hours will they take to complete the job together?

To determine how long it will take Master Plumber A and Master Plumber B to complete the job together, you can first calculate the work rates of each plumber.

Master Plumber A can complete the job in 8 hours, meaning that in one hour, A completes 1/8 of the job. Similarly, Master Plumber B, who takes 10 hours to complete the job, finishes 1/10 of the job in one hour.

When they work together, their combined work rate adds up their individual rates. Therefore, the combined rate of A and B is:

1/8 + 1/10

To add these fractions, you first find a common denominator, which in this case is 40. Rewriting the fractions gives:

(5/40) + (4/40) = (9/40)

The combined rate of 9/40 means that together they complete 9/40 of the job in one hour. To find out how long it takes for them to finish the entire job, you can take the reciprocal of their combined rate:

Time = 1 / (9/40) = 40/9

Calculating 40 divided by 9 gives approximately 4.44