1.
每次都相同
设A中红黑分别为X,Y,那么B中分别有红黑26-X,26-Y
因为X+Y=26,Y=26-X
所以A中黑牌Y等于B中红牌26-X
2.
设A有蛋X个,B则有100-X个,每个卖Y1,Y2
(100-X)Y1=15,XY2=6+2/3,XY1=(100-X)Y2
20(100-X)^2=45X^2
X=40
A有40个蛋B有60个蛋
3.
设每只狗产生速度V,距离为L,预计时间为T
5VT=5V*1+3V(T+1)=L
T=4
5VT=5V*1+3VT+2V(50/V)=L
V=100/3
L=2000/3