Rate of Jenny = 1/ 8.4 minutes
Rate of Mofor = 1/13.3 minutes
We know time and rate are inverses of each other.
So, if they work together, their rates would be:
[tex]\frac{1}{8.4}+\frac{1}{13.3}[/tex]The time they will take will be the inverse of this, thus:
[tex](\frac{1}{8.4}+\frac{1}{13.3})^{-1}[/tex]So, let's calculate it:
[tex]\begin{gathered} (\frac{1}{8.4}+\frac{1}{13.3})^{-1} \\ =5.1484 \end{gathered}[/tex]That is around 5.15 minutes.
