They both take 17.1 min to make the pizzas.
Step-by-step explanation:
Ron can do a job in 30 mins =[tex]\frac{1}{30}[/tex]
Jeff can do a job in 40 mins = [tex]\frac{1}{40}[/tex]
They both work together = [tex]$\frac{1}{40}+\frac{1}{30}$[/tex]
We have to take LCM of 30 and 40 as 120, so that the denominator becomes equal, also we can add them.
= [tex]\frac{3}{40 \times 3}+\frac{4}{30 \times 4}=\frac{7}{120}[/tex]
Further we get, [tex]\frac{120}{7}=17.1 \mathrm{mins}[/tex]
They both work for 17 .1 mins to make the same number of pizzas.
