How can you build pig pens so you can put nine pigs in four pens that each pen has an odd number of pigs?
How can you build pig pens so you can put nine pigs in four pens that each pen has an odd number of pigs?
如果把9头猪放进4个猪圈里且每个猪圈有奇数头猪，这样的猪圈该怎样建呢？
How can you build pig pens so you can put nine pigs in four pens that each pen has an odd number of pigs?
如果把9头猪放进4个猪圈里且每个猪圈有奇数头猪，这样的猪圈该怎样建呢？