Answer :
From the information given we can say that the work of rate of Beth is 6h/floor. When they work together with Mike, we can represent the situation with the equation:
[tex]\frac{t}{B}+\frac{t}{M}=1[/tex]Where B is the rate of Beth and M is the rate of Mike, t is equal to 2.4 hours. Replacing the values we have:
[tex]\begin{gathered} \frac{2.4}{6}+\frac{2.4}{M}=1 \\ 0.4\text{ }+\frac{2.4}{M}=1\text{ (Dividing)} \\ \text{ }\frac{2.4}{M}=1\text{ }-0.4\text{ (Transposing 0.4 to the other side of the equation)} \\ \frac{2.4}{M}=0.6(\text{ Subtracting)} \\ \frac{2.4}{0.6}=M\text{ (Isolating M)} \\ 4\text{ =M} \\ \text{Answer is: Mike takes 4 hours to tile a floor} \end{gathered}[/tex]