小红从家到学校22.5千米，他每天骑车上学，往返一次共需1.5时，小红平均每时行多少千米？

equation:x=(22.5*2)/1.5

30

甲数是乙数的80%，乙数是丙数的75%，则甲数是丙数的多少

equation:x=(4/5)/(4/3)

60%

有两根彩带，一根长24厘米，另一根长36厘米，现在要把它们剪成同样长的短彩带，且没有剩余，每根短彩带最长是多少厘米？

equation:x=2*2*3

12

(1/2)/(1/4)+(3/4)．

equation:x=(1/2)/(1/4)+(3/4)

2(3/4)

用x、3、6和12这四个数组成比例，x不可能是多少

equation:x=36

36

三年级同学去果园劳动，男生30人，女生39人．如果每3人分成一组，一共要分多少组？

equation:x=(30+39)/3

23

6个同样大小的圆柱铅锭，可以铸成多少个与它等底等高的圆锥形铅锭．

equation:x=6*3

18

总长度为910厘米的墙体包括10个均匀隔开的正方形柱子(墙体两端均有柱子)．柱子边长为10厘米．那么，两相邻柱子间的距离是多少厘米．

equation:x=(910-10*10)/(10-1)

90

一根铁丝，第一次剪去(1/5)，第二次剪去剩下的(1/4)，第三次剪去第二次剩下的(1/3)，第四次剪去第三次剩下的(1/2)，最后只剩下10cm，这根铁丝长多少厘米．

equation:x=10/(1-(1-(1-(1-(1/5))*(1/4)-(1-(1/5))*(1/4))*(1/3)-(1-(1-(1/5))*(1/4)-(1-(1/5))*(1/4))*(1/3)-(1-(1-(1/5))*(1/4)-(1-(1/5))*(1/4))*(1/3))*(1/2)-(1-(1-(1-(1/5))*(1/4)-(1-(1/5))*(1/4))*(1/3)-(1-(1-(1/5))*(1/4)-(1-(1/5))*(1/4))*(1/3)-(1-(1-(1/5))*(1/4)-(1-(1/5))*(1/4))*(1/3))*(1/2)-(1-(1-(1-(1/5))*(1/4)-(1-(1/5))*(1/4))*(1/3)-(1-(1-(1/5))*(1/4)-(1-(1/5))*(1/4))*(1/3)-(1-(1-(1/5))*(1/4)-(1-(1/5))*(1/4))*(1/3))*(1/2)-(1-(1-(1-(1/5))*(1/4)-(1-(1/5))*(1/4))*(1/3)-(1-(1-(1/5))*(1/4)-(1-(1/5))*(1/4))*(1/3)-(1-(1-(1/5))*(1/4)-(1-(1/5))*(1/4))*(1/3))*(1/2))

50

一个平行四边形的底和高同时扩大到原来的3倍，那么这个平行四边形的面积扩大到原来的多少倍．

equation:x=3*3