Answer: it will take them 2.03 hours working together
Step-by-step explanation:
A laborer can do a certain job in 5 days. His unit rate of working will be 1/5
a second laborer can do the same job in 6 days, His unit rate of working will be 1/6
The third laborer can do the same work in 8 days. His unit rate of working will be 1/8
If they work together, they would be working simultaneously at their individual rates. This means that their unit rates are additive.
Their combined rates will be
1/5 + 1/6 + 1/8 = (24 + 20 + 15)/120
= 59/120
Assuming it will take t hours for them to to finish the job. Then their combined unit rate will be 1/t
59/120 = 1/t
59t = 120
t = 120/59 = 2.03 hours
