4.16几经

AI;45
AG:31
1. 6个盘子，一蓝5白，摆成一圈。五种坚果，其中有N和R，别的不知。如果N或R之一必须放在蓝盘子中，其他盘子各放一个坚果，共有几种摆法。
[确认]  240
2. 复利的计算，四年。P(1+A)4
3. . what’s the remainder of 2^k divided by 10.
(1) k is dividable by 10
(2)  k is dividable by 4
4 . ask the unit digit of p^xy
(1) the unit digit of p^x is 1
(2) the unit digit of p^y is 1
[确认]: D
5. . A must choose 2 of 4 types of floor, and choose 2 of 6 paint of colors. Ask how many combination of types of floor and different paint colors.
[确认]:90
6.Y=km+b ask the slope of K
(1) line y=(1-m)b+a parallel Y
(2) Y intersect with line y=2x+3 at point (2.7)
7. . Class  Number  Mean  Median
A    a       82    85
B    b       79    75
Ask if the median of a+b more than the mean of a+b
(1) the sum of a+b is 79
(2) a=42, b=37
8.三个直角三角形连在一起，并且第一个三角形为等腰直角三角形，直角边为a，其余2个直角三角形中都有一边为a。已知第三个三角形斜边长度，求a为多少。