9514 1404 393
Answer:
3.5 hr
Step-by-step explanation:
We assume that "the same rate" means effort per tree is a constant. "Effort" is measured as the product of lumberjacks and hours. Then ...
(lumberjacks)(hours)/trees = (6)(2)/15 = (8)(t)/35
Multiplying by 35/8, we have ...
(35/8)(12/15) = t = (3·4·5·7)/(2·3·4·5) = 7/2 = 3.5
It will take 8 lumberjacks 3.5 hours to cut down 35 trees.
