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The distance between AB and a is 150 km, and a and B start from ab at the same time. If they go in the same direction, B can catch up with a in 4 hours; if they go in the same direction, B can catch up with a in 1.5 hours Hour meet, find the average speed of a and B cars
Two vehicle speed sum = 150 △ 1.5 = 100 km / h
Speed difference = 150 △ 4 = 37.5km/h
The speed of vehicle B is (100 + 37.5) △ 2 = 68.75 km / h
The speed of car a is 100-68.75 = 31.25 km / h
Have a good time
Solving the equation (2x-1) / 6 = (5x + 1) / 8
The denominators on both sides are divided by 2 = 2x-1 of 3 = 5x + 1 of 4 at the same time, and then cross multiplied. 4 (2x-1) = 3 (5x + 1) 8x-4-15x-3 = 0 - 7x-7 = 0 - 7x = 7x = - 1
A. B the distance between the two places is 200 km. The fast and slow trains start from the two places at the same time and run in opposite directions. After 2.5 hours, the two trains meet. It is known that the speed ratio of the fast and slow trains is 3:2. How many kilometers did the two trains travel when they met?
200 ﹣ 2.5 ﹣ 3 + 2 = 80 ﹣ 5 = 16 (km) fast train: 16 × 3 × 2.5 = 120 (km) slow train: 16 × 2 × 2.5 = 80 (km) answer: fast train runs 120 km, slow train 80 km
1 / 7 can be converted into a circular decimal. The number on the 2009 digit after the decimal point is a: 1, B: 4, C: 5D: 7
1 / 7 is 7-bit-1 cycle, cycle section is 14285712009 / 7 = 287.0, so it should be 1, select a
Cars travel 100 kilometers per hour and buses 80 kilometers per hour. If two cars start from the gas station at the same time and travel along the same road in opposite directions, it will be the same time for two hours
How long is the highway between the two places to the destination
Let me tell you the truth, 100 + 80, find the sum of speed. 180 times 2, because their speed and time are equal to their distance. Finally, it is equal to 360 km, 360 km is equal to 360000 M. because the rate of progress between them is 1000, so add 3 o's
I hope the landlord chooses me and answers honestly
① In rational numbers, if a number is not a positive number, then it must be a negative number. ③ real numbers with endless square root are called irrational numbers
① - a must be negative ()
② In rational numbers, if a number is not positive, it must be negative ()
③ The real number whose square root is not enough is called irrational number ()
④ Irrational numbers are all infinite decimal ()
⑤ A number with a root is an irrational number ()
⑥ There is no minimum real number ()
⑦ The smallest integer is zero ()
⑧ The square of any real number is nonnegative ()
① - a must be negative (wrong)
② In rational numbers, if a number is not positive, it must be negative (wrong)
③ Irrational numbers are real numbers whose square root is endless
④ Irrational numbers are all infinite decimals
⑤ Numbers with roots are irrational (wrong)
⑥ There is no minimum real number (pair)
⑦ The smallest integer is zero (wrong)
⑧ The square of any real number is nonnegative
There are two trains running from a and B at the same time. The slow train runs 70 kilometers per hour, and the fast train runs 10 kilometers more than the slow train. After four hours, the two trains run 23 times of the whole journey. On the railway diagram with the scale of 1:10000000, what is the distance between a and B in the diagram?
The speed of express train is 70 + 10 = 80 (km \ \ h), the distance of two trains: (70 + 80) × 4 = 600 (km), 600 ／ 23 = 900 (km); 900 km = 90 million cm, 90 million × 110 million = 9 (CM); a: the distance between a and B is 9 cm
If the average of the first four numbers is 7 and the average of the last two numbers is 10, what are the first and fifth numbers
If the average number of five numbers is 9, then the sum of five numbers is 9 * 5 = 45, if the average number of the first four numbers is 7, then the sum of the first four numbers is 7 * 4 = 28, then the fifth number is 45-28 = 17, and the fourth number is 10 * 2-17 = 3,
It's an even number, and it's a multiple of 2 and 3. It's a two digit number. After you exchange the position with the number on the ten digit number, it's a multiple of 5. What's the number?
It's a multiple of two and three at the same time
Then the number must be a multiple of the least common multiple 6 of 2 and 3
Because you exchange the position with the number on the ten digit, it is a multiple of 5, so the ten digit of the original number must be 5
Because it's a double-digit number, and it's a multiple of 5 and 6 in the tens, so this number is 54
A number consisting of five tens, four 0.1, three 0.01 and one 0.001 is______ ．
The number composed of five tens, four 0.1, three 0.01 and one 0.001 is 50.431
RELATED INFORMATIONS
- 1. The distance between the two places measured on the map of scale 1:6000000 is 10 cm. A and B vehicles leave from the two places at the same time and meet after 6 hours. It is known that the speed ratio of a and B vehicles is 11:9. When the two vehicles meet, how many kilometers does a vehicle travel?
- 2. How many liters does a small car use for one kilometer
- 3. The original number of female workers in a workshop accounted for 14% of the total number of workers in the workshop, and then the number of male and female workers increased by 4 respectively. At this time, the number of female workers accounted for 13% of the total number of workers in the workshop. How many were the original workers in the workshop?
- 4. If a number is reduced by 60%, the result is 2 / 3 of 120. Find this number
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- 7. Calculation: (1 / 3a-0.2b) (- 0.2b-1 / 3a)
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