一头牛重500千克,两头牛重 千克,合 吨.
甲数除以乙数的上是2.75,那么甲数与乙数的最简整数比是 .
= ÷ = %=6: .
÷20=0.8==20÷ = %
==16÷ = %
9÷ ==0.375=15: = %