已知甲，乙，丙，三个数的和是290，甲是乙的3倍，又比丙少十，求甲数是多少？

290-10=2803+3+1=7280÷7=4040×3=120甲数是120

这是一个和倍问题，和倍问题的基本数量关系式是：和÷（倍数+1）=一倍数，一倍数×倍数=几倍数。解题时，我们先根据数量关系找到两个量之间的倍数关系和两个量的和，先求出一倍数，然后再求出几倍数就可以了。

这道题根据甲是乙的三倍，那么说明乙是一倍量甲是三倍量，联系上下文应该是甲比丙少10，所以只要把丙去掉10就和甲一样多了，那么总数也要去掉10就说明丙也是乙的三倍，所以合起来就是3+3+1=7倍就对应280，然后一除就把一倍量乙数求出来了，再乘3就是甲数了

你会英语吗？

是几年级的英语呢？

五年级的

好的，你发给我帮你看看

In China, the preparations for the new year's day began before the new year's day. Every household should thoroughly clean their houses, clothes and clothes. The clothes on the bed and all the utensils are considered to sweep away the bad luck and make the house ready for good luck.In the morning I sweep the floor，I will wash the dishes in the evening。All the brooms are put away on New Year's Eve, so good luck won't be swept away.

应该没有这么长吧？

那就把最后一段去掉

就用总分的方式不要总了

In China, the preparations for the new year's day began before the new year's day. Every household should thoroughly clean their houses, clothes and clothes. The clothes on the bed and all the utensils are considered to sweep away the bad luck and make the house ready for good luck.In the morning I sweep the floor，I will wash the dishes in the evening。

亲，还有问题吗？