Help me! Math Puzzle 15

Using the drawer principle, so that 40% of the non-excellent Chinese are all excellent in mathematics, then 65%-(100%-60%)=25% are excellent. Or use the Venn diagram, try to make the overlapping parts that are excellent in Chinese and mathematics as few, and the repetition part can be 65%+60%-100%=25%.

Class 62 students scored excellent in Chinese and 65% in mathematics.

When 40% of the Chinese scores are not excellent, the number of students with excellent scores in the two subjects is the lowest, which is 65%-40%=25%.

At least 25% of the class is achieved with excellent grades in two subjects

Hehe, it's very simple, you think too much 60%+65%-100%=25%.

Give a tip.

The sum of those who are good at mathematics and those who are not good at mathematics is exactly 100%, 65% who are excellent, and only 35% who are not excellent

60% of the people are excellent in the language, and only 40% are not excellent

A maximum of 35% of the class will be without excellent results in either subject, and at least 60% of the class will be excellent in both subjects

At least 25% are required to be excellent "at least" how much, then consider the most extreme cases. Let's assume that the remaining 35% of the students have achieved excellent Chinese proficiency, and that there are still 25% of the students in the class (60%-35%)=25% who have achieved excellent Chinese on the basis of excellent mathematics.

60%+65%-x=100%

then x = 25% (that is, both Chinese and math are excellent added twice, so subtracting once is 100%)

65%-5%=60% (person).

A: At least 60 percent of the class.

A 60% indicates a percentage of language scores at Merit.

b 65 per cent indicates a proportion of Distinction in Mathematics.

In fact, find the ratio of A and B to be excellent at the same time.

Assuming that the excellence of Chinese and mathematics is independent of each other and does not affect each other, this assumption is completely reasonable for doing this kind of problem, otherwise there is no way to calculate:

Then the proportion of students who are excellent in both language and mathematics is a and b a b 60% 65% 39

Supplement: Proportion of excellent in language or mathematics a or b a b a and b) 60% 65% 39 86

Let's say the class is 100 people. You draw a circle on the paper to represent the whole class. The horizontal shade indicates that the language is excellent, and the vertical line shade indicates that the mathematics is excellent, and what you can see is that there must be at least 25 overlapping people in both shades. The answer is 25%.

Set the class size to x, list the equations, and then solve the equations. Or.

The title of this question should be incomplete.

The answer should be a range.

The answer is 25% 60%.

Workers produce 4 parts in 5 minutes. At this production efficiency, 8 workers produce parts (8) in 10 hours.

2.A bus stop. There are 5 different routes, each of which departs every few minutes. The first departure is at 6 a.m. and the second departure at the same time at 7 a.m. (30 a.m.).

3.Kindergarten children play games, and each child gets as many balls. In this way, there are 12 balls left, and then 12 balls are added, so each child gets exactly 12 balls, and these children have a total of (12) people, and the original balls (132).

4 = 1, 8 10 60 5 = 960 (pcs).

hour 30 minutes is to find the least common multiple.

3. If it is 12 children, there will be no 12 balls left in the first score, and the children should be 24, and there are 11 24 12 276 balls

According to the title, it is known that the drink that one person gets is.

2+2 3+2 6=18 6=3 bottles.

Then there are 180 3 = 60 people.

Each person planted 1 + 5 2 + 4 3 + 3 5 = 163 30 trees, 60 people planted a total of 60 163 30 = 326 trees.

Those comrades are also correct in using equations, but the calculations are not responsible.

If the work efficiency is x (or 1), the total amount of work is 30x (work efficiency * working time = total work), the time spent on the parts in front of 2 3 is (2 3 * 30x) x = 20 hours, and the time spent on the parts in the back 1 3 is (1 3 * 30x) (x + 1 4x) = 8, a total of 28 hours was spent, 2 hours earlier than the original plan.

The solution consists of 15x=10y=6z

Let x=2t, y=3t, z=5t

Again, by 3x-y+2z=26

That is, 6t-3t+10t=26

i.e. 13t = 26

i.e. t=2, so x=2t=4

y=3t=6

z=5t=10

Do it perpendicular to the straight line of the flock, because the line between the two points is the shortest, if you throw a bone in front of you, will the dog run along the curve to chase the bone? No, it will run straight because the dog also knows that the line between two points is the shortest.

2.Complementary angle of angular BOD: angular cob

Complementary angles of the angular coe: angular eod

Opposite apex angle of angular BOC: angular AOD

Proof: ab is the diameter.

bca=90°

od⊥ac∠oda=90°

oda=∠bca

OD BCO is the midpoint.

od=1/2bc

The connecting OC coa is an isosceles triangle.

oca=40°

aoc=180-40-40=100°

Dear, please [answer], you are the motivation for me to answer the question, thank you.

1. (2000-1600) 2000 100%=20% Refrigerators are 20% less than color TVs

2500-1600) 2500 100%=36% Refrigerators are 36% less than air conditioners

2. (2500-2000) 2500 100%=20% Color TV is 36% less than air conditioner

2000-1600) 1600 100%=25% Color TV is 25% more than refrigerator