甲乙两人分别以每小时6千米，每小时4千米的速度从相距30千米的两地向对方的出发地前进．当两人之间的距离是l 0千米时，他们走了多少小时？
+62.5%= 78×9.9+7.8= 7×
÷7×=
+
=
3.2万+1.8万= 4×2.7×0.25= 5﹣0.25+0.75= 0.42﹣0.32=
直接写出得数
1÷
= 0.4+4.73=
÷
=+
=
×
=
+0.8=
×
÷×=（
+
）×120=
口算：
÷62.5%=
÷8= 1.8÷
= 0.375+
﹣0.01=
×
÷×=
0.25×4÷
=
×
÷×= 19÷
= 0.125×
×8= 6.4×﹙1
﹣1.25﹚=
直接写得数
36+48= 920﹣460= 570÷10= 12.5÷0.5=
4﹣2.4= 0.125×8= 3.6×25%=
×
=
3.5+4.7= 0.23÷0.1=
÷3=÷
=
直接写得数．
1÷
=
×
=
+
= 2﹣
=
4.2×0.5= 0.25×0.6= 246+198=
﹣
=
=
=
= 84.6+4=
= 10÷0.5=
= 603×39≈
4980÷51≈ 9.3÷0.03=
÷2÷= 9﹣
﹣
．