Fruit sales

The seller sold 40% of the fruit on the first day, 2/3 of the rest on the second day, and the remaining 20 kg on the third day. How much fruit did he sell in those three days?

Final Answer:

x =  100 kg

Step-by-step explanation:

$$\begin{gathered} r_1=40\%=\frac{40}{100}=\frac{2}{5}=0.4 \\ {r}_1\cdot x+\frac{2}{3}\cdot (x-r_1\cdot x)+20=x \\ 0.4\cdot x+\frac{2}{3}\cdot (x-0.4\cdot x)+20=x \\ 0.4\cdot x+2/3\cdot (x-0.4\cdot x)+20=x \\ 0.6x=60 \\ x=\frac{60}{0.6}=100 \\ x=100=100\text{kg} \end{gathered}$$

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