展开全部

题目列表

题目内容
$$a_{1}=2$$,$$a_{2}=3$$,当n≥3时,$$a_{n} = a_{n-1} * a_{n-2}$$.What is the value of $$a_{8}$$?
S={1,2,3}
T={1,2,3,4}
Quantity A: The number of different four-digit integers formed by elements from Set S(all elements can be used by more than once)
Quantity B: The number of different three-digit integers formed by elements from Set T(all elements can be used by more than once)
There are three different frames and five different pictures. Now choose three pictures to put into frames, one for each frame, how many possible ways to put them.
How many points (r, s) can be formed so that r < s, and that the x and y-coordinates of the point are both selected from odd integers between 1 and 399, inclusive?
In how many different ways can 5 identical small balls be placed in 3 different baskets so that each basket must have at least one small ball?
A, B, C, D and E need to take seats such that A and B sit next to each other. How many ways can they arrange the seats?
Four different books A, B, C, D are to be placed on the shelf, A and B must be put together. How many different ways can the four books be placed?
Four different toys need to be put into three different kids. At least one toy should be given to each kid. In how many ways can these toys be arranged?
The 8 items A, B, C, D, E, F, G, and H are to be displayed on a straight line. In how many ways can the items be displayed if item B must be placed in any position that is to the right of item A,and item C must be placed in any position that is to the right of B?
In a box of 10 electrical parts, 2 are defective. If someone selects 2 electrical parts randomly, what is the probability that neither of the parts will be defective?
Give your answer as a fraction.
How many positive divisors of 16 are multiples of 3?
If someone selects two numbers from 5,8,9,9,9 without replacement, what is the probability that the sum of the two numbers is multiple of 3?
Give your answer as afraction.
There are 12 bags of spice, which includes 5 different flavors. Among these, one bag`s flavor is C and 5 bags is of cherry flavor. What is the probability that one C flavor and one cherry flavor are drawn out when someone draw two bags of spice from the 12 bags?
Give your answer as a fraction.
4 out of 10 students have a certain feature. When selecting 3 out of these 10 students to form a committee, what is the probability that at least two selected students have such feature?
Give your answer as a fraction.
If someone selects one letter from JOHNONS and one letter from JONES,what is the probability that the two letters selected are the same?
Give your answer as a fraction.
Three typists work for four companies,each company has one document,what is the probability that three typists all receive documents?
Among Event A, Event B and Event C, Event B and Event C are mutually exclusive, 0 < P(A) < 1, P(A)=2P(B)=3P(C)

Quantity A

$$\frac{2}{3}$$

Quantity B

P(B or C)


There five red socks, four blue socks and three yellow socks in the box. They are same except for color. Randomly take one from the box, and then put it back and randomly take another one. What is the probability that both socks are yellow?
Event A and event B are independent event. If the probability that even A occurs is 0.4 and event B occurs is 0.3, what will be the probability that at least one event occurs?
If it takes P and S together 1 hour and 20 minutes to fill $$\frac{2}{3}$$ of a swimming pool, and another 50 minutes for S alone to fill the rest, how many hours will it take if P is supposed to fill the entire swimming pool alone?

共收录:

25000 +道题目

236本备考书籍

最新提问