Bricklayers

When a bricklayer works to redeem the house in 8 days, the other bricklayer will be finished in 10 days. How long will it take to make three such houses together?

Correct answer:

x =  13.3333 d

Step-by-step explanation:

$$\begin{gathered} x_1=\frac{1}{\frac{1}{8}+\frac{1}{10}}=\frac{40}{9}\doteq 4.4444\text{d} \\ x=3\cdot x_1=3\cdot \frac{40}{9}=\frac{3\cdot 40}{9}=\frac{120}{9}=\frac{40}{3}\text{d}=13.3333\text{d} \end{gathered}$$

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