GRE
$$x+y$$
$$\sqrt{(x^2+y^2)}$$
$$a_{6}$$
$$25^{3}(0.2)^{10}$$
N
125
The number of 3-digit integers all of whose digits are even (the same number could be used for more than once)
The number of 3-digit integers all of whose digits are odd (the same number could be used for more than once)
The total number of 4-digit positive integers that can be formed using only the digits in set S
The total number of 3-digit positive integers that can be formed using only the digits in set T
$$(d^{2})!$$
$$(d!)^{2}$$
14!
15!-14!
25000 +道题目
5本备考书籍