Let the purchase price be 1 and the profit be x%.
1×( 1+x %)=( 1- 10%)×( 1+x %+ 18%)
x=62%
Someone bought a stock last year, and the stock fell by 20% last year. How much should it go up this year to keep the original value?
If the original value is 1, increase x.
( 1-20%)+x×( 1-20%)= 1
80%x=20%
x= 16%
1)(200410/training school "Yuanming Cup" Mathematics Invitational Test Paper No.7) A store sells two cars of different brands a day, each of which costs168,000 yuan, of which one makes a profit of 20% at cost and the other loses 20%. Does this shop sell these two cars at a loss or at a profit? How much is the money?
If the cost of each brand car is X and Y ten thousand yuan, then (1+20%)x= 16.8, (1-20%)y= 16.8.
X= 14，y=2 1。 If you sell the first brand car, you earn16.8-14 = 28,000 yuan, and if you sell the second brand car, you lose money.
21-16.8 = 42,000 yuan, then the store lost 4.2-2.8= 1.4 million yuan a day.
Changfeng farm brigade has 23 hectares of land, and plans to use 37.5% of the land to grow cotton, and the rest is medium corn and soybeans.
(1) How many hectares of land are planted with corn and soybeans?
Please give the formula and answer.
(2) If the land planted with corn accounts for 60% of the total land planted with soybeans and corn, how many hectares of land are planted with soybeans?
1.23 * (1-37.5%) =14.375 (hectare)
2.14.375 * (1-60%) = 5.75 (hectare)
The number 1.A is 20% less than the number b, so the number b is more than the number a.
2. The daily water production (in milliliters) is shown in the figure. The water exhaled by the lungs accounts for 80% of the daily water output.
(400: lung exhalation; 500: ; 100: solid waste; 1500: water-borne waste)
.
100
500
celebrity
1500
3. There is a pile of candy, of which milk candy accounts for 45%. After adding 16 pieces of fruit candy, milk candy only accounts for 25%. So, there are toffee blocks in this pile of candy.
4. Put 25g of salt into100g of water to make brine. What's the salt content of this brine? This salt water is 200 grams, with grams of salt.
A
B
C
5. An elastic ball landed from point A, bounced to point B, then landed on a platform 20 cm high, bounced to point C, and finally landed (pictured). The height of each bounce is 80% of the falling height. It is known that point A is 68 cm higher than point C, so the height of point C from the ground is cm.
At a meeting yesterday, there were 700 more male delegates than female delegates. Today, the number of male delegates decreased by 65,438+00%, while the number of female delegates increased by 5%. Today, * * * 1995 people attended the meeting, so others attended the meeting yesterday.
7. There are two stores, A and B. If the profit of store A increases by 20% and the profit of store B decreases by 10%, then the profits of these two stores are the same. The profit of Store A is 50% of that of Store B. 。
8. Enlightened Publishing House publishes a book. The cost of each book this year has increased by 65,438+00% compared with last year. But the original price was maintained, so the profit per book dropped by 40%. However, the number of books issued this year has increased by 80% compared with last year. Therefore, the percentage of total profits from the issuance of such books this year has increased.
9. Party A and Party B start from A and B at the same time, face to face, and the speed ratio is 3:2. After they met for the first time, the speed of A increased by 20% and the speed of B increased by 30%, so when A arrived at B, B was still 14 km away from A, so the distance between A and B was.
10. There are two piles of chess pieces, pile A has 350 spots and 500 Bai Zi, and pile B has 400 spots and 100 Bai Zi. In order to make 50% of the spots in the A-pile and 75% of the spots in the B-pile, we should get the A-pile from the B-pile; Sunspots.
One, Bai Zi.
Second, answer the question.
1 1. A shrewd boss used the following methods to determine the selling price of a commodity: Suppose the quantity of the commodity is n, then the selling price of n commodities (unit: yuan) is: cost per piece? ( 1+20%)? After n is calculated, it is made into an integer multiple of 5 (only increasing but not decreasing). According to this pricing method, the following results are obtained: 1 50 yuan; 2 pieces of 95 yuan; 3 pieces 140 yuan; 4 pieces 185 yuan; ..... If the cost of each piece is whole yuan, what is the cost of each piece of this commodity?
12. Profit percentage =? 100%
Last year, an electronic product was sold at 80% price and made a profit of 20%. Due to the low purchase price this year, when it was sold at 75% of the same price, it earned a profit of 25%. How much is the amount?
13. Beijing Jiuzhang Bookstore implements a preferential measure for customers: 5% discount for each book purchase from 200 yuan to 499.99 yuan, and 10% discount for each book purchase from 500 yuan and above (including 500 yuan). If a customer buys books in a bookstore three times, it will be cheaper to merge them for the first time than to buy them separately 13.5 yuan; If buying three books together is 38.4 yuan cheaper than buying three books separately, I know that the price of the first book is the price of the third book. Ask the customer how much this book costs for the second time.
14. There are three pipelines, A, B and C. The pipeline A flows out the brine containing 20% salt at a speed of 4g per second, B flows out the brine containing 15% salt at a speed of 6g per second, and C flows out the water at a speed of 10g per second. After the pipe C is opened, stop the flow for 2 seconds, then stop the flow for 5 seconds, and then stop the flow for 2 seconds.
———————————— Answer the case ————————
1.20%? ( 1-20%)=25%
2.400? (400+500+ 100+ 1500)= 16%
3. 16? [( 1-25%)? 25%-( 1-45%)? 45%]=9 (block)
4. The salt content is:
200 grams of this brine contains 200 salts? 20%=40 grams
5.[68+20? ( 1-80%)]? ( 1-80%? 80%)-68= 132 (cm)
6.( 1995-700? 90%)? ( 1+5%+90%)? 2+700=2 100 (person)
7.( 1- 10%)? ( 1+20%)=75%
8. Suppose the cost of each book is 4 yuan, the price is 5 yuan, and the profit of each book is 1 yuan, but the current cost is
4? (1+ 10%)=4.4 yuan, the price is still 5 yuan, and the profit per volume is 0.6 yuan, which is 40% lower than the original profit per volume.
But the number of albums released this year has increased by 80% compared with last year. If 65,438+000 copies were issued last year, then 65,438+000 copies will be issued this year? (1+80%)= 180 (volume).
Original profit 1? 100= 100 (yuan), and now the profit is 0.6? 180= 108 (yuan). So the total profit this year is higher than last year (108- 100)? 100=8%.
9. After meeting, the speed ratio between Party A and Party B is 1? (1+20%): (1+30%) =18:13, so the distance between a and b is 14? (km)
10. If you want to get a bunch of sunspots from B and Bai Zi, there are:
Solution = 175, =25.
1 1.45? [( 1+20%)? 1]=37.5
12.[75%? ( 1+25%)]? [80%? ( 1+20%)]= .
13. The first and second * * * payables 13.5? 5%=270 yuan, so the price of the third book must be in
500-270 = more than 230 yuan, so that the total price of the three books can reach a discount of 10%. If you buy it three times, you can also get a 15% discount on the price of the third book, so:
The total price of the third book is 5 18-270=248 yuan.
The total price of the first book is 248 = 155 (yuan).
The total price of the second book is 270-155 =115 (yuan).
14. Because of 60? (5+2) = 8 ...4, so the running time of pipeline C is 5? 8+2=42 (seconds), so the percentage of salt in the mixed solution is