Wood 11

Father has 12 1/5 meters long wood. Then I cut the wood into two pieces. One part is 7 3/5 meters long. Calculate the length of the other wood.

Correct answer:

b =  4 ³⁄₅ = 23/5 m

Step-by-step explanation:

$$\begin{gathered} f=12\frac{1}{5}=12+\frac{1}{5}=\frac{12\cdot 5+1}{5}=\frac{60+1}{5}=\frac{61}{5}=12.2\text{m} \\ a=7\frac{3}{5}=7+\frac{3}{5}=\frac{7\cdot 5+3}{5}=\frac{35+3}{5}=\frac{38}{5}=7.6\text{m} \\ b=f-a=\frac{61}{5}-\frac{38}{5}=\frac{61-38}{5}=\frac{23}{5}=\frac{23}{5}\text{m}=4\frac{3}{5}\text{m}=4.6\text{m} \end{gathered}$$

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