Problema Solution
John can do a certain job in 3 hours,sarah can do the same job in 7 hours,Jane can do the same job in 5 hours,how long will the job take the three of them working together?
Answer provided by our tutors
1 hr work of all = 1/3 + 1/7 +1/5 = (35+15+21)/105 = 71/105
hence they can finish all together in = 105/71 hrs