Olympiad questions, how hard is the Olympiad?

The percentage in this question should be the quality score.

Let the initial brine have salt x and water y, and the water added each time is z.

According to the title.

x/(y+z)＝15％

x/(y+2z)＝12％

Take the countdown on both sides.

y+z)/x＝100/15

y+2z)/x＝100/12

z x 100 60 can be found

Then (y+3z) x 10

then x (y+3z) = 10

That is, the salinity is 10 after adding the same water for the third time

Solution: Let the salt content in the original brine be Mo, the quality of the brine is M1, and the mass of each water addition is M2.

m0/(m1+m2)=

mo/(m1+2*m2)=012

Eliminate m0 to get m1=3*m2, and substitute either formula to get m0=, then the m0 (m1+3*m2)= is 10%.

Let the original brine water be m and the salt be n, and the water added each time is x3 20=n (m+n) one.

3 25=n (m+n+x) two.

Reverse (i) and (ii) formulas.

20/3=(m+n)/n

25/3=(m+n+x)/n

That third time is n (m+n+2x).

becomes(m+n+2x) n=10

Then n (m+n+2x)=

That is, the salt content becomes 10%.

The Olympiad is a competition for the selection of a small number of outstanding talents, and it is very difficult. Anyone is allowed to participate in this competition, but it is generally recommended by the school after passing the school competition. In the end, those who can participate in the national competition are very top-notch talents from each school.

Each of the Olympiads covers a wide range of events that go far beyond what the average secondary school student learns, so young people who participate in this competition need to learn more about this aspect on their own in order to be more competitive.

The Olympiad aims to enable the majority of young people to develop intellectually through competition, and to create opportunities and conditions for a small number of outstanding young people to stand out and become outstanding talents. This activity has been carried out extensively in our country and has achieved outstanding results. Students who have achieved excellent results in the Olympiad are eligible to participate in the independent entrance examination.

There are five main Olympiads (Mathematics, Physics, Chemistry, Biology, Informatics) and several other Olympiads (Astronomy Olympiad, Earth Science Olympiad, Linguistics Olympiad, etc.).

Olympiad awards:

1. The method for judging the results, the proportion of winners and the number of winners in the national competition and the provincial competition shall be determined by the organizer.

2. The winning standards of the provincial competition shall be determined by the organizer, and the number of first prize winners of the competition shall be controlled by the competent unit.

3. The certificate of the national competition and the first prize certificate of the provincial competition shall be uniformly printed by the competent unit. Provincial competitions.

The certificates of the second and third prizes shall be uniformly printed by the organizer.

4. The award certificate of the national competition (the final and the first prize of the provincial competition) shall be jointly issued by the competent unit and the organizer, and the provincial competition.

The second and third prize certificates will be issued by the organizer.

5. The competent unit of the competition shall publicize the list of first prize winners within the specified time.

China does not have its own Olympic Day.

June 23 is International Olympic Day. On June 23, 1894, the International Olympic Committee was officially established in Paris, and in order to commemorate this historic day, the International Olympic Committee has designated June 23 as the International Olympic Day since 1948.

If I had to talk about Olympic Day in China, it would be August 8. The 29th Summer Olympic Games were held in Beijing, China on August 8, 2008. In order to commemorate the success of the Beijing Olympic Games, since 2009, August 8 has been designated as the "Full Name Fitness Day" every year.