Answer: 5[tex]\frac{1}{3}[/tex] days
Step-by-step explanation:
6 tractors = 8 days
double the tractors = half the time
(2 x 6 tractors = [tex]\frac{1}{2}[/tex] x 8 days)
1.5 the tractors, means [tex]\frac{1}{1.5}[/tex] of the time
1.5 x 6 tractors = [tex]\frac{1}{1.5}[/tex] x 8 days
9 tractors = [tex]\frac{8}{1.5}[/tex]
= 5.33 days
NOTE: I really think the answer is 6 days but I could not figure out a mathematical way to get that answer.