Please ask for a few difficult Olympiad questions

1.Solution: Set up a ticket gate to check x tickets in one minute, the original Y people, and Z people come every minute.

According to the question: y+30x 5*z*30

y+20x＝20*z*20

x＝3z y＝60z

60z+3z*10）/10z＝9

A: You need to open 9 of them.

2.Solution: Set up a ticket gate to check x tickets in one minute, the original Y people, and Z people come every minute.

According to the title: y+18x 3z*18

y+6x＝5z*6

x＝2zy＝18z

18z z 18 (min).

60-18 42 (mins).

A: The queue starts at 10:42.

3.Solution: Set the original resource x, consume y per person per year, and add z every year according to the topic: x+90z 11 billion * y * 90x + 210z 9 billion * y * 210

z 7.5 billion y

x 315 billion y

z y 7.5 billion y y 7.5 billion.

A: It could feed up to 7.5 billion people.

1.Solution: If the number of tickets checked at a ticket gate in one minute is 1, then the passengers who come every minute are:

5 30 6 20) (30 20) 3 copies.

So there are passengers before the start of ticket checking: 5 30 30 3 = 60 copies.

So it takes ten minutes for the line to disappear, and it takes (60 3 10) 10 9 to open.

2.Slightly (do it like the first question).

3.Let's assume that the amount of resources consumed per person per year is 1.

Let the original resources be x, and the new resources will be y

x+90y=11 billion*90

x+210y=9,000,000,000,000*210

The solution is x=9 billion, y=10.9 billion.

10.9 billion 1 = 10.9 billion (people).

Only the new resources are consumed and the existing resources are protected, and there is potential for continuous development. So the planet can feed up to 10.9 billion people.

If the half-day workload of all people is A, with the big grass on the left and the small grass on the right, it can be concluded that the daily workload of 1 person is A 4, and the half-day workload is A 8, so there are 8 people in total.

There are x people in the lawn mowing team.

Large meadows: Small meadows:

Equation: Solution: x=8

Hello: Eight to get a profit according to the price of eighty-five discounts** eight: 12 (45-30) = 120 yuan each according to the price of eighty-five percent off ** to get a profit:

120 8 = 15 yuan according to the price of eighty-five discount ** than the original price of each less selling: 45-15 = 30 yuan original price: 30 (1-85%) = 200 yuan.

Solution: Let the purchase price of this commodity be X yuan.

The price is (x+45) yuan.

x+45）× = （x+10）×12-12x+306-8x = 120=0

186 =x =155

Price: 155 + 45 = 200 (yuan).

Set the price to A

8*a=Right?