## Li Ming bought a story book. On the first day, he read 25% of the whole book, and on the second day, he read two fifths of the whole book. There are still 42 Pages left. How many pages are there in this book? There are 7200 peach and pear trees in an orchard. The number of peach trees is 4 / 5 of that of pear trees. How many peach and pear trees are there in this orchard?

Li Ming bought a story book. On the first day, he read 25% of the whole book, and on the second day, he read two fifths of the whole book. There are still 42 Pages left. How many pages are there in this book?

1-0.25-0.4=0.35

42/0.35=120

Xiao Ming read a book. On the first day, he read 6 pages more than 1 / 6 of the whole book. On the second day, he read 8 pages less than 1 / 8 of the whole book. In the end, there are 172 pages left. There are a total of 172 pages in this story book

What's the formula

240, let this book have X pages, X - ((x / 6 + 6) + (x / 8-8)) = 172

Beibei read a 180 page story book. He read one sixth of the whole book on the first day and one third of the whole book on the second day. How many pages did he read in two days?

180×（1/6+1/3）=180×1/2=90

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