Jiangsu Education Edition Sixth Grade Mathematics Book 13 Page 1-9 Answer.

Solve equations.

x+60%x=48？ x-25%x=27？ x-36%x=0.52

Solution: 1.6x=48? Solution: 0.75x=27? Solution: 0.64x=0.52

x=30 x=36 x=0.8 125

2. Lin Mingyu has collected 120 stamps, of which foreign stamps account for 25% of China stamps. How many foreign stamps and China stamps did Lin Mingyu collect?

Solution: Suppose there are X stamps in China and 25% X stamps abroad.

? X+25% x =120 25% x = 96× 25% = 24 (sheets)

? 1.25x= 120

x=96

Lin Mingyu collected 24 foreign stamps and 96 China stamps.

3. Young Pioneers collected 28 fewer animal specimens than plant specimens, of which 80% were animal specimens. How many samples were collected from each of these two samples?

Solution: We assume that X-rays are collected from plant specimens and 80% from animal specimens.

? X-80% x = 28 80% x =140× 80% =112 (pieces)

? 0.2x=28

? x= 140

A: Collect 40 plant specimens and 2 animal specimens1/kloc-0.

There are 96 peach and pear trees. Calculate the number of peach and pear trees according to the following conditions.

(1) Peach trees are three times as large as pear trees.

Solution: There are X pear trees and 3x peach trees.

x+3x=96？ 3x=24×3=72 (tree)

? 4x=96

x=24

There are 24 pear trees and 72 peach trees.

5. Solve the equation.

2/ 15x+ 1/6x = 2/5 1/2x- 1/3x = 1/ 10

Solution:? 3/ 10x=2/5 Solution:? 1/6x= 1/ 10

? x=4/3？ x=3/5

6. Xinzhuang Nursery has cultivated 880 pine saplings this year, which is 10% more than originally planned. How many pine seedlings were planned to be cultivated?

? 880 (100%+10%) = 800 (tree)

A: It was originally planned to cultivate 800 pine saplings.

7. In 2003, there were 20,200 returned overseas students in China, an increase of 13% over 2002. In 2002, tens of thousands of China people returned from studying abroad. (Figures shall be kept to two decimal places)

2.02÷ (100%+13%) ≈1.79 (ten thousand people)

A: In 2002, 6.5438+0.79 million people returned from China.

8. Guangming Livestock Farm has raised 900 beef cattle.

Beef cattle are 20% less than cows. How many cows are there? There are 25% more cows than beef cattle. How many cows are there?

900÷ (100%-20%) =1125 (head)? 900+900×25%= 1 125 (head)

A: There are 1 125 cows. ? A: There are 1 125 cows.

9. The actual construction investment of the sewage treatment tank is less than the original plan 10%.

(1) saved 48,000 yuan. How much did you originally plan to invest?

? 4.8÷ 10%=48 (ten thousand yuan)

A: The original planned investment was 480,000 yuan.

(2) The actual investment is 432,000 yuan. What is the original planned investment?

? 43.2 (100%-10%) = 48 (ten thousand yuan)