How to solve real problems? How to solve real problems

Do it yourself, you can summarize the teacher's words.

1) Not necessarily, because I don't know how much each has planted. If 100 seeds are planted, the second seed will sprout more, but if the first seed has 200 grains and the second seed has 100 grains, the first type will sprout more.

2) The germination rate cannot exceed 100%. Because the number of germinated grains must be less than or equal to the number of grains of the seed.

Hello classmates.

Solution: If B rests for x days, then A rests for 2x days.

Equations can be listed according to the meaning of the question.

25-2x) 1 30+(25-x) 1 40=1 to get x=5

Answer: B rests for 5 days.

There is another way, let's tell you together:

If two people do it together for 25 days, it can be completed: 25 * (1 30 + 1 40) = 35 24

Much more than it actually is: 35 24-1 = 11 24

B does one day A can do two days: 1 40 + 2 30 = 11 120 So, the number of days B rests is: (11 24) (11 120) = 5 days.

Solution: If B rests for x days, then A rests for 2x days.

25-x)/40+ (25-2x)/30=15/8-x/40+5/6-x/15=1

11x/120+35/24=1

11x/120=11/24

x=5A: Then B rested for 5 days.

1. The average price of renting a small boat is 60 yuan per person, and the average price of renting a large boat is 40 yuan per person. So the more big ships, the more money you save. 5 large boats and 1 small boat should be rented.

Total money = 200x5 + 180x3 = 1540 (yuan) Answer: 2, the area of the road = (7 + 7 + 5 + 5) x1 = 24 (square meters) The number of bricks = 14x24 = 336 (block) Answer

Analysis: Catch up with the problem:

distance difference = 300 km; Speed difference = 180-80 = 100 km/h.

Then time = distance difference speed difference = 300 100 = 3 hours, which means that the EMU can catch up with the ordinary express train 3 hours after departure.

In this problem, in fact, the rice plays a confusing role and has nothing to do with the solution of the problem.

By drawing a water line with white paint along the inner wall of the swimming pool, it can be seen that the actual length of the water line is the perimeter of the cross-section of the swimming pool

60+25) 2=170 meters.

It is composed of two lengths and two widths on the four sides of the rectangle, and because the length is 60 meters and the width is 25 meters, the total length = 2 (60 + 25) = 170 meters.

2*(60+25)=170 meters. According to the title, the length of the water line is equal to the perimeter of the pool.