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What does △ mean in Olympiad Mathematics?
Like x in the equation, it's an unknown number
What's the meaning of! In Mathematical Olympiad
4! = 4x3x2x1,5! = 5x4x2x2x1, n! = n (n-1) (n-2) (n-3) x3x2x1
What is Olympiad Mathematics and what does it mean?
Profound mathematics-
What is Olympiad Mathematics
Olympic Mathematics Competition
There are 100 parts in 10 bags, 10 in each bag. In 9 bags, each part is 50g, and in 1 bag, each part is 49G. When these 10 bags are mixed together, can you find out the bag of parts by weighing it with a balance?
1) The 10 bags were numbered as 1,2,3,4,5,6,7,8,9,10
(2) Take one part from bag 1, two parts from bag 2 and ten parts from bag 10
(3) If all the 55 parts are 50g, the total weight should be 2750g
(4) If the weighed weight is a gram less than 2750g, each part in the bag numbered a weighs 49G
Four different unit fractions, in which two denominators are odd and two denominators are even, and the sum of two fractions with odd denominator is equal to the sum of two fractions with even denominator. What are the four true fractions satisfying the above conditions?
Analysis:
According to the meaning of the question, because it is a true fraction, it can only be calculated from 2. Because the denominator of 2 is an odd fraction and the denominator of 2 is the sum of even fractions, we find out the least common multiple of these four numbers, and these four numbers should contain this least common multiple. Therefore, we can determine that three of these four numbers are 2, 3 and 5, and their least common multiple is 30, so these four numbers are 2, 3, 5 and 30
Moreover, 1 / 3 + 1 / 5 = 8 / 15 = 16 / 30, 1 / 2 + 1 / 30 = 16 / 30,
So the four true fractions are 1 / 2, 1 / 3, 1 / 5, 1 / 30
The average price of mixed sugar is 9.13 yuan per kilogram. It is known that there are 35 kg of milk sugar, 10.3 yuan per kilogram, and 8.5 yuan per kilogram of fruit sugar
I want a way of thinking
Milk sugar 35x (10.3-9.13) = 40.95 yuan
Fructose 40.95 ÷ (9.13-8.5) = 65 Jin
If other problems are added,
There are 600 people outside the playground. The number of people who come every minute after opening the door is certain. 10 people enter every minute at each entrance. There is no queue at four entrances after 20 minutes, and no queue at six entrances after how many minutes?
Four entrances 20 minutes into the 10 × 4 × 20 = 800 (people), each minute the new people are 800-600 △ 20 = 10 (people) 600 people, through six entrances into the need for 600 △ 10 △ 6 = 10 (minutes) 10 minutes, there are new people 10 × 10 = 100 (people), and then into the 100 people need 100 △ 60 = 1 (minutes) 40 (people) 2
There are two trains, one is 220m long, 22m per second, and the other is 200m long, coming head-on at the speed of 20m per second. How long does it take for them to complete a wrong trip?
It takes x seconds to set a wrong train
22x-20x=200+220
The solution is x = 210 seconds
5080 ml = () l = () cubic decimeter 375 cubic centimeter = () cubic decimeter
A composite number has at least () divisors
A square wood is 3 meters long, and the ground is a square with side length of 3 decimeters. Its volume is () cubic decimeters
5080 ml = 5.08 L = 5.08 cubic decimeter 375 cubic centimeter = (0.375) cubic decimeter 3
two hundred and seventy
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