Answer:
The time it takes them to grade the essays if they work together is 1.857 hours
Step-by-step explanation:
- Let t1 is time taken by Professor J = 3 hours
- Let t2 is time taken by the assistant = 5 hours
- Let tb is the time taken by both
The formula for “Work” Problems that involve two persons is
[tex]\frac{1}{t1} + \frac{1}{t2} =\frac{1}{tb}[/tex]
<=> [tex]\frac{1}{3} + \frac{1}{5} =\frac{1}{tb}[/tex]
<=> [tex]\frac{1}{tb} = \frac{8}{15}[/tex]
<=> tb = [tex]\frac{15}{8} = 1.875 hours[/tex]
The time it takes them to grade the essays if they work together is 1.857 hours
