Calculation problem 5:3 + 3:1 = () 6:2-4:3 = () seek Calculation questions 5 and 3 / 4 + 3 and 1 / 3 = () 6 and 2 / 3-4 and 3 / 4 = () Beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg, beg

nine and one-twelfth
one and eleven-twelfths

One third (1 / 3) of a bag of rice is used and 8 kg is added to it, which is exactly four fifths (4 / 5) of the original

8÷【4/5-（1-1/3）】
=8÷【4/5-2/3】
=8÷2/15
=60 (kg)

Xiaojun bought a 30 page children's story book. He can read up to four pages a day. How many days will it take at least to finish the book?

30 △ 4 = 7 (days) ---- 2 (pages)
It will take at least eight days to finish reading the book

Xiao Jun read a story book on his weekends. He read two fifths of the whole book in two days, and just read 30 pages. How many pages is the book?

Xiao Jun read a story book. When he read 3 / 10 of the whole book, he had 20 more pages left than he had read. How many pages does the book have?

Use (1-3 / 10) to get the rest. Suppose the whole book has x pages, then
（7/10x）-（3/10x）=20,
（4/10x）=20
X = 50 pages

Xiao Jun read a story book. On the first day, he read 1 / 2 of the book. On the second day, he read the remaining 1 / 2. On the third day, he read the remaining 1 / 2. On the third day, he read ↓
What's the percentage of the book?

（1-1/2）×（1-1/2）×1/2
=1/2×1/2×1/2
=1/8
A: Xiaojun read one eighth of the book on the third day

Xiaoqiang read a book, 15 pages a day. After 4 days, he quickened his pace and read another 25 pages of the whole book. There are still 30 pages left. How many pages are there in this story book?

A: this story book has 150 pages

Xiaoqiang read a story book. He read two fifths of the whole book every day. He read 84 pages in seven days. How many pages is the book?

Because I read 2 / 15 of the whole book every day, 7 * 2 / 15 = 14 / 15 for 7 days
Because I read 84 pages in seven days, 84 / (14 / 15) = 90
A: there are 90 pages in this book
I hope I can help you!

Xiaoqiang read a story book. He read two fifths of the whole book every day and 84 pages in seven days. How many pages are there in this book?

7 read 2 / 15 * 7 = 14 / 15, that is 84 pages, so 1 / 15 = 84 / 14 = 6, so the whole book has 6 * 15 = 90 pages

If you finish a story book in 10 days, you will finish 7 / 10 of the book in 7 days. Right or wrong

Not necessarily. There may be days when I read more and days when I read less