Two mechanics, martin and gordon, are working on your car. martin can complete the work in 4 hours, while gordon can complete the work in 2 hours. how many hours does the maintenance take if they work together? a. one half b. three fourths c. six eighths d. four thirds

In one hour Martin working alone can complete 1/4 of the work and in one hour Gordon working alone can complete 1/2 of the work.
Working together they can complete 1/4 + 1/2 = 3/4 of the work in one hour. Therefore it will take 4/3 hours to complete the work when they work together.
The correct answer is d. four thirds.

Well, you can find that out using this formula :

4 x 2    / 4+2

4 x 2    / 6

    = 8/6
 
    =4/3

So the answer is option d. four thirds

Hope this helps