A carpenter

A carpenter had a 10-meter piece of lumber from which he cut into two pieces. One of those pieces was 5 2/3 meters long. How long was the piece that remained?

Correct answer:

b =  4 ¹⁄₃ = 13/3 m

Step-by-step explanation:

$$\begin{gathered} s=10\text{m} \\ a=5\frac{2}{3}=5+\frac{2}{3}=\frac{5\cdot 3+2}{3}=\frac{15+2}{3}=\frac{17}{3}\doteq 5.6667\text{m} \\ a+b=s \\ b=s-a=10-\frac{17}{3}=\frac{10\cdot 3}{3}-\frac{17}{3}=\frac{30}{3}-\frac{17}{3}=\frac{30-17}{3}=\frac{13}{3}=\frac{13}{3}\text{m}=4\frac{1}{3}\text{m}=4.3333\text{m} \end{gathered}$$

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