GRE
$$100!+99!$$
$$\frac{101!}{100}$$
x+y
150
The area of EFGH
$$\frac{1}{4}$$ the area of the circle
The standard deviation of the distribution of X
The standard deviation of the distribution of Y
The number of different groups of 2 kittens that can be chosen from a litter of 8 kittens
The number of different groups of 6 puppies that can be chosen from a litter of 8 puppies
The probability that exactly two adjacent digits of the number selected will be the same
$$\frac{1}{5}$$
25000 +道题目
236本备考书籍