Xiaogang has three times as many story books as Xiaojun. It is known that Xiaogang and Xiaojun each have 82 story books. How many are Xiaojun's

Xiaogang has three times as many story books as Xiaojun. It is known that Xiaogang and Xiaojun each have 82 story books. How many are Xiaojun's

If there are x copies of Xiaojun, then Xiaogang 3x will have (x + 3x) / 2 = 82 and x = 41, which means that Xiaojun has 41 books

Xiaojun, Xiaoliang and Xiaogang go to the bookstore to buy the complete story of moving primary school students. If you use the money brought by Xiaojun to buy the book, it is still 55 yuan less; if you use the money brought by Xiaoliang, it is still 69 yuan less; if you use the money brought by the three people, it is still 30 yuan more. It is known that Xiaogang has brought 37 yuan. How much does it cost to buy a complete set of stories of primary school students?

Suppose the book costs X Yuan
The result is: (x-55) + (x-69) + 37 = x + 30
x-55+x-69+37=x+30
2x-87=x+30
x=117
A: it costs 117 yuan to buy a complete set of touching primary school students' stories

Xiaogang and Xiaojun each have some balls. If Xiaogang gives Xiaojun four balls, they will have the same number; if Xiaojun gives Xiaogang four, Xiaogang's ball is three times that of Xiaojun How many balls did they have?

There were 20 Xiaogang and 12 Xiaojun
The steps are as follows:
Let Xiaogang have X balls and Xiaojun have y balls
The following equations can be listed
x-4=y+4
3(y-4)=x+4
When the two equations are combined, the following results are obtained
x=20,y=12

Xiaogang and Xiaoming go to the bookstore to buy books. Xiaogang takes 2 yuan less than 5 / 6 of Xiaoming's. Xiaogang takes 48 yuan. How much does Xiaoming take? Explain it carefully

She brought X Yuan with her
5x/6-2=48
x=60

Xiaohong, Xiaohua and Xiaogang each have some storybooks. Xiaohong gave Xiaohua 2 copies and Xiaohua gave Xiaogang 3 books. After Xiaohong gave Xiaogang 3 books, each of them had 15 books. How many books did each person have What do you mean by each step? Why do you do this?

After Xiaohua gave Xiaogang three more copies, all three of them had 15 copies. Xiaogang's original 15-3 = 12 copies. After Xiaohua got two copies and sent three copies, it was 15 copies. Xiaohua's original 15 + 3-2 = 16 copies, and Xiaohong's two copies gave 15 copies, and the original 15 + 2 = 17 copies

Xiao Gang read a story book. On the first day, he read a third of the whole book, and the next day he read eight pages. At this time, the ratio of the number of pages he has read to the number of pages he has read in the future is, Two to three, how many pages is the book? It's better to explain it The future is not careful to see more

Seen = 2 × (2 + 3) = 2 / 5
Total = 8 × (2 / 5-1 / 3) = 120 pages

Xiao gang spent one-third of the money to buy a pen and 4 yuan to buy a story book. At this time, the ratio of the money spent to the remaining money was 5:4. How much money was left

Hello:
Use all: 5 ^ (5 + 4) = 5 / 9
At this time, there is still: 4 × (5 / 9-1 / 3) × (1-5 / 9) = 8 (yuan)

Xiaoming has 35 extra-curricular books. It's just five seventh of Xiaogang's. Xiaohong's extracurricular books are just six seventh of Xiaogang's

Xiaogang has 35 ￣ 5 / 7 = 49 copies and Xiaohong has 49 × 6 / 7 = 42 copies

Xiaoming has 35 books, 5 / 7 of Xiaogang's, and 6 / 7 of Xiaogang's. how many books does Xiaohong have?

Xiaogang has 35 △ 5 / 7 = 49 copies
Xiaohong has 49 × 6 / 7 = 42 copies

Xiaoming and Xiaogang have more than 200 books. If Xiaoming gives Xiaogang x books, Xiaoming's books are 3 / 7 less than Xiaogang's; if Xiaogang gives Xiaogang x books, Xiaogang's books are Then Xiaogang's books are 3 / 8 less than Xiaoming's, so how much is x? The answer is 36, but I want to know the process

1－3/7＝4/7
4/7÷（1＋4/7）＝4/11
1－3/8＝5/8
1÷（1＋5/8）＝8/13
（ 8/13－4/11）÷2＝18/143
Because they have more than 200 books, 143 < 200
Therefore, 143 × 2 = 286 > 200
18/143＝36/286
Therefore: x = 36