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Several mathematical problems, the urgent solution process 1. An enterprise has received the task of producing movable houses for the earthquake stricken area. The enterprise has nine production workshops. Now each workshop has the same number of original finished product movable houses, and the production capacity of each workshop is the same. There are two groups of inspectors, group A and group B, of which there are eight inspectors in group A. two days ago, after the inspection of all finished products (the original and those produced in these two days) in the first and second workshops was completed, It will take another three days to inspect all the finished products in the third and fourth workshops. At the same time, the inspectors in group B will also inspect all the finished products in the remaining five workshops in these five days. If the inspection speed of each inspector is the same, what is the number of inspectors in group B? 2. 15. On May 12, 2008, an 8.0 earthquake occurred in Wenchuan, Sichuan Province, which caused serious casualties and property losses. A unit actively carried out the activity of "donating money to teaching assistants" to help the poor students in a school in the disaster area. It is known that there are 1862 students in the high school and junior high school. The standard for senior high school students is 500 yuan per semester, and the standard for junior high school students is 350 yuan per semester, But 30% of the students in senior high school do not accept the subsidy because of their better family conditions? 3. If the real number m ≠ N and (8m + n) / (8N + m) = (M + 1) (n + 1), then M + n =?
One question and three questions are like upstairs
Question 2: because 7 out of every 10 students in high school get 500 yuan, that is 3500 yuan, so the average person is 350 yuan. That is to say, every student needs 350 yuan for donation. So it's good to hold on: 350 * 1862 = 651700 yuan
When a crosses the finish line in the 60 meter race, it is 10 meters ahead of B and 20 meters ahead of C. if B and C continue to rush to the finish line at the original speed, how many meters ahead of C when B crosses the finish line
Under the effective control, the noise of a residential area decreased year by year. In 2011, the noise decreased by 3% compared with 2010, in 2012, the noise decreased by 4% compared with 2011, and in 2013, the noise decreased by 5% compared with 2012
It takes 6 days for a cruise ship to go upstream from a to B, 4 days for a cruise ship to go downstream from B to A. if other factors are not taken into account, how long does it take for a plastic floating object to float from B to a
If it takes 12 people 2 hours to dig a pool 1 meter long, 1 meter wide and 1 meter deep, how many hours does it take for 6 people to dig a pool 2 meters long, 2 meters wide and 2 meters deep
The clock on the square will ring several times at what time. The interval between the two sounds is 5 seconds. From the first sound, it takes several seconds to judge that the time is 12 o'clock
The sum of the three primes is 50. Then the maximum value of the product of the three primes is
Mr. Lu is fond of raising tropical fish. He keeps colorful fairy fish and tiger skin fish in his aquarium. Now I know that the product of the number of these two kinds of fish multiplied by each other is just the sum of the fish when I look in the mirror. What is the difference between the product and the sum
1. When a crosses the finish line in the 60 meter race, it is 10 meters ahead of B and 20 meters ahead of C. if B and C continue to rush to the finish line at the original speed, how many meters ahead of C when B crosses the finish line
&Nbsp; leading C: 20 - (60-20) × 10 ÷ (60-10) = 20-8 = 12m;
2. Under the effective control, the noise of a residential area decreased year by year. In 2011, the noise decreased by 3% compared with 2010, in 2012, the noise decreased by 4% compared with 2011, and in 2013, the noise decreased by 5% compared with 2012
1-（1-3%）×（1-4%）×（1-5%）≈1-0.885=0.115=11.5%
3. It takes 6 days for a cruise ship to go upstream from a to B, 4 days for a cruise ship to go downstream from B to A. if other factors are not taken into account, how long does it take for a plastic floating object to float from B to a
&Nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; flow velocity = (1 / 4-1 / 6) △ 2 = 1 / 24;
&It takes 1 / 24 = 24 days for plastics to float from a to B
4. If it takes 12 people 2 hours to dig a pool 1 meter long, 1 meter wide and 1 meter deep, how many hours does it take for 6 people to dig a pool 2 meters long, 2 meters wide and 2 meters deep
1×1×1÷（12×2）=1/24；
&Nbsp; & nbsp; & nbsp; & nbsp; & nbsp; need: 2 × 2 × 2 (1 / 24 × 6) = 8 ／ 1 / 4 = 32 hours
5. The clock on the square will ring several times at what time. The interval between the two sounds is 5 seconds. From the first sound, it takes several seconds to judge that the time is 12 o'clock
&There are 11 intervals for 12 knocks at 12 o'clock;
&It takes 5 × 11 = 55 seconds;
&6. The sum of the three prime numbers is 50. Then the maximum value of the product of the three prime numbers is [1482]
In the expansion of (2x-1) 5, find the sum of (1) coefficients; (2) binomial coefficients; (3) binomial coefficients of even number terms; (4) absolute values of coefficients
(1) Let (2x-1) 5 = A0 + a1x + a2x2 + +Let x = 1 to get the sum of the coefficients: A0 + A1 + --- + A5 = 1; (2) the sum of the binomial coefficients C05 + C15 + − C55 = 25 = 32. (3) the sum of the binomial coefficients C15 + C35 + C55 = 12 × 25 = 16. (4) let x = - 1, then A0 − a1 + A2 − A3 + A4 − A5 = (− 3) 5 = − 243, so the sum of the absolute values is 243
High school, plane vector
AB is a vector, | a | = 6, | B | = 4, and the angle between a and B is 60 ° to find | a + B|
(a + B ` 2 = | a | ` 2 + | B | ` 2 + 2 vector a * vector b = 36 + 16 + 2 * 6 * 4 * cos60 = 76
|A + B | = Geng No. 76
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