4/5- 1/5=3/5
54/(3/5)=90
2. 30 people in a school line up. How many people are there in this square? How many people are there on the outermost two floors?
* * *: 30 * 30 = 900 people
The outermost two floors: 4 * (30-1)+4 * (30-2-1) = 4 * (29+27) = 224 people.
3. A group of students moved a pile of bricks, each with 8 bricks, leaving 14 bricks; Everyone moved 9 yuan, and the last person only moved 6 yuan. Q: How many students are there in this group?
9-6=3
14+3= 17
9-8= 1
17/ 1= 17 people
4. In an exam, the teacher gave each class A four sheets of paper and each class B three sheets of paper, and * * * issued 7 16 sheets of paper; If there are three cards for class A and four cards for class B, 705 cards will be issued. How many people are there in each class?
If everyone has 7 716+705 =1421.
No one has 1, so: 142 1/7=203, which means ***203 people.
3 per person, then 3*203=609.
There are 7 16-609= 107 people in class a.
Class B 705-609=96 people.
Xiaogang goes to school from home. If he walks at a speed of 50 meters per minute, he will be one minute late. If you walk at a speed of 60 meters per minute, you can arrive 2 minutes earlier. How far is Xiaogang's home from school?
Set the specified time x minutes.
50(x+ 1)=60(x-2)
10x= 170
X= 17 minutes
50 * (17+1) = 900m.
There are 80 peach trees, apricot trees and apple trees in the orchard, among which apple trees account for a quarter of the total. The ratio of peach trees to apple trees is 5: 4. How many apricot trees are there in the orchard?
The original question was wrong, so I changed it.
Apple tree: 80* 1/4=20
Peach Tree: 20*5/4=25
Apricot tree: 80-20-25=35