A number after the decrease of 20%, the percentage increase of old number back to new.The prize:Some decrease 20% IE cut in 1/5 of the value of that. So to increase the number of additional new 1/4 of it i.e. the initial number. Lesson 3:Some increased 25% they must reduce the percentage left was the old number.The prize:Some increased 25% i.e. Add 1/4 of itSo, the new numbers are decreased by 1/5 of its news value is 20% of it was the original number.Lesson 4:The amount of water in the fresh grass is 55%, in the dry grass is 10%. Ask 100 kg of fresh grass exposure we are how many kilos of dried grass grams.The prize:The amount of grass available in fresh grass is:100-55 = 45%Or 100 kg of fresh grass has 45 kg of grass.But in the dry grass is also 10% water. So 45 kg of grass is 90% of the mass of dry grass.So, 100 kg of fresh grass hay number obtained is:Response of 50 kg.Lesson 5:Sea water contains 4% salt. Need to pour more how many grams 400 grams of sea water into the vicissitudes to salt ratio in the solution is 2%.The prize:The amount of water the salt contained in sea water: 400 g400 x 4:100 = 16 (g)Containing 2% salt is:Keep there are 100 g water, 2 g of salt16 g of salt to the water quantity needed is:100:2 x 16 = 800 (g)The amount of water to add is:800-400 = 400 (g)Response of 400 g.Article 6:The area of a rectangle will change if its length increases up to 10% and reduced the width of it go 10%The prize:Call length is 100 x aMeasurements are width x 100 bMeasurements of area is: 10 000 x a x bThe new length measurements: 110 x anew width measurements are: 90 x bNew area measurements are: 9900 x a x bNew area measurements less former area measurements are:10 000 x a x b-900 9 x a x b = 100 x a x bArticle 7:The amount of water in the fresh seeds is 20%. There are 200 kg fresh grain after drying lightly go 30 kg.Calculate the ratio% water in the seeds have dried.The prize:The water initially contained in 200 g fresh seeds are:200:100 x 20 = 40 (kg)The number of grain drying is also:200-30 = 170 (kg)The amount of water remaining in the 170 kg of grain has dried is:40-30 = 10 (kg)The ratio% water contained in the seeds have dried, are:10:170 = 5.88%Response of 5.88%Article 8:The United States on new year price increase of 20% in comparison with November. In January the United States back 20% of the lower price. Question:United in January compared with the United way, would be more expensive and more expensive how much percent.The prize:United new year than November is:100 + 20 = 120 (%)Price after the lunar new year is also:100-20 = 81 (%)After the lunar new year than November is:United after the lunar new year than November is:100-96 = 4 (%)Response No. 4%Article 9:A person buying a promissory type 3, with 1.9% interest rate 1, and value promissory 6000 000 VND. Asked after 3 months that field people about how much money interest and capital. Know that the money, capital, before entering into the capital of the following month.The prize:Which of the following month in comparison with the previous month is:100 + 1.9 = 101.9 (%)Capital money, second is:The money capital, Tuesday is: Capital funds and interest rate after 3 months is: Meeting number: 6,348,539.154 vnd Article 10:The price of vegetables in March often more expensive than February is 10%. Vegetable prices in April back in March of 10% cheaper. The price of vegetables, 2 expensive or cheaper vegetable prices in April?The prize:If the prices of vegetables, 2 is 100%So the vegetable prices in March are:100 + 10 = 110 (%) The price of vegetables, 2Vegetable prices in April are:100-10 = 90 (%) vegetable prices in March and by:So April vegetables cheaper vegetables. -----------------------* HOMEWORK: Lesson 1: a 10% discount, book reviews books on staff 1/6 but the store is still 8% interest rate.Question: On the store is usually the interest rate percentage.Lesson 2: a sales person being 15% of the sale price in words. Ask him how many percent of your purchase price?Lesson 3: A shop selling rice is 25% interest on the purchase price. Ask the shop how much margin is the percentage of the selling price.Post 4: last school year, a store selling discount 20% play. Asked with the same amount of money as before, a student will buy more is how much percent of the play.Lesson 5: find the area of a rectangle, knowing that if the length is increased by 20% and reduced 20% width measurements, the reduced area 30 m 2Lesson 6: the rice output of the area A area B is more than 26% even though the area of the area of A larger area only B is 5%. Ask the region's harvest yield A lot more than the area B is what percent?Lesson 7:80% increase in workload. Asked to increase the number of workers more percentage to 20% increase in labor productivity?Lesson 8: worker's wage increase of 20%, 20% off price. With this new salary questions, the new amount will buy more of the old row percentage?
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