Answer:
Option 3.43 hours
Step-by-step explanation:
Dorothy and Rosanne are baking cookies for a party. Rosanne alone can finish the cookies in 6 hours.
So per hour work done by Rosanne will be = [tex]\frac{1}{6}[/tex]
Dorothy can finish the cookies in 8 hours, so per hour work done by Dorothy = [tex]\frac{1}{8}[/tex]
So per hour work done by both Dorothy and Rosanne = [tex]\frac{1}{6}+\frac{1}{8}=\frac{7}{24}[/tex]
Therefore total time taken by Dorothy and Rosanne = [tex]\frac{24}{7}=3.43[/tex]
Both will finish the work in 3.43 hours.
Option B. 3.43 hours is the correct option.