Li Hong is wearing a red coat and a white hat. She is very energetic?

Li Hong is wearing a red coat and a white hat. She is very energetic?

Li Hong wears a red coat and a white hat. She is very energetic

What color is blue and purple

It depends on the proportion of the two colors
If there is more blue, it will be purplish blue in the end
If there is more purple, it will be bluish purple in the end
Of course, if the color ratio is very different, less color can be ignored

It takes 10 days for Zhang to complete the work of Party A alone and 15 days for Li Dan to complete the work of Party A alone and 20 days for Li Dan to complete the work of Party B alone______ Day

Assuming that work B is "1", Li's work efficiency is 120 and Zhang's work efficiency is 115, the reasonable arrangement should be that Li completes work a alone, and Zhang does (8 days) work B alone, and then Zhang and Li cooperate to complete the remaining amount of work B, sharing (1-115 × 8) / (120 + 115) + 8 = 715 ／ 760 + 8 = 4 + 8 = 12 (days). A: it takes at least 12 days to complete these two tasks The answer is: 12

Li Hong and Zhang Ming each have 20 stamps. How many stamps does Li Hong give Zhang Ming? Zhang Ming has 50% more stamps than Li Hong?

Set to X
20+x=(20-x)*1.5
The solution is x = 4

There are three kinds of balls in the box. The ratio of the number of yellow balls to the number of red balls is 2:3, and the ratio of the number of red balls to the number of white balls is 4:5?

The ratio of yellow, red and white spheres: (2 × 4): (3 × 4): (5 × 3) = 8:12:15, 8 + 12 + 15 = 35175 × 835 = 40, 175 × 1235 = 60, 175 × 1535 = 75; a: 60 red spheres, 40 yellow spheres and 75 white spheres

Press 2 red 3 Blue 2 red 3 blue The 49th bead is () bead, and there are () blue beads in the first 49 beads

Press 2 red 3 Blue 2 red 3 blue There are (29) blue beads in the first 49 beads

There are four beads in a bag, two of which are red and two are blue. Except for the color, the other characteristics are the same. If any two beads are taken from this bag, the probability that they are all blue is ()
A. 12B. 13C. 14D. 16

There are 3 × 4 = 12 possibilities, and two results are blue, so the probability of being blue is 16

At present, there are 16 different cards, including 4 red, 4 yellow, 4 blue and 4 green. Three of them should not be the same color, and there should be at most one red card___ (answer with numbers)

According to the meaning of the question, regardless of the special circumstances, there are c316 kinds of methods, of which each card takes three, there are 4c34 kinds of methods, two red cards, there are C24 · C112 kinds of methods, so the method of c316-4c34-c24 · C112 = 560-16-72 = 472

At present, there are 16 different cards, including 4 red, 4 yellow, 4 blue and 4 green cards. Three of them are required to be taken out. These cards cannot be of the same color, and there is no more than one red card. The number of different kinds of cards is ()
A. 232B. 252C. 472D. 484

According to the meaning of the title, regardless of special circumstances, there are a total of c316 methods, of which each card takes three, there are 4c34 methods, two red cards, there are c24c112 methods, so the method is c316-4c34-c24c112 = 560-16-72 = 472, so choose C

At present, there are 12 different cards, including 3 red, 3 yellow, 3 blue, and 3 green cards. It is required that the three cards should not be of the same color, and there is one red card. The different methods are as follows

81 species? 3 * 3 * 3