Petr book pages

Peter read 3/8 of a book in the first week, 1/4 in the second week, and 1/10 in the third week. The book has 240 pages. How many pages does Peter have left to read?

Final Answer:

x =  66

Step-by-step explanation:

$$\begin{gathered} n=240 \\ r=\frac{3}{8}+\frac{1}{4}+\frac{1}{10}=\frac{15}{40}+\frac{10}{40}+\frac{4}{40}=\frac{15+10+4}{40}=\frac{29}{40}=0.725 \\ w=1-r=1-\frac{29}{40}=\frac{1\cdot 40}{40}-\frac{29}{40}=\frac{40}{40}-\frac{29}{40}=\frac{40-29}{40}=\frac{11}{40}=0.275 \\ x=w\cdot n=\frac{11}{40}\cdot 240=\frac{11\cdot 240}{40}=\frac{2640}{40}=66 \end{gathered}$$

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