Answer: It will about 1.88 hours or 1 hour 52.5 minutes to clean the stadium if they work together .
Step-by-step explanation:
Given : Time taken by Kevin to clean a stadium = 5 hours
Rate of work done by Kelvin =[tex]\dfrac{1}{5}[/tex]
Time taken by Chris to clean a stadium = 3 hours
Rate of work done by Chris =[tex]\dfrac{1}{3}[/tex]
Let t be the time taken by both of them to clean the stadium together.
According to the question , we have
Rate of work done together = Rate of work done by Kelvin+Rate of work done by Chris
[tex]\dfrac{1}{t}=\dfrac{1}{5}+\dfrac{1}{3}\\\\ \Rightarrow\ \dfrac{1}{t}=\dfrac{3+5}{15}\\\\ \Rightarrow\ \dfrac{1}{t}=\dfrac{8}{15}\\\\\Rightarrow\ t=\dfrac{15}{8} =1.875[/tex]
[tex]t=1+0.875[/tex] hours
[tex]t=1\text{ hour }+0.875(60)\text{ minutes}[/tex] [∵ 1 hour = 60 minutes]
[tex]t=1\text{ hour }+52.5\text{ minutes}= \text{1 hour 52.5 minutes}[/tex]
Hence, It will about 1.88 hours or 1 hour 52.5 minutes to clean the stadium if they work together .
