一堆煤,用去它的40%,剩下2.4吨,如果用去它的62.5%,剩下多少吨?

问题描述:

一堆煤,用去它的40%,剩下2.4吨,如果用去它的62.5%,剩下多少吨?

2.4÷(1-40%)×(1-62.5%)
=2.4÷0.6×0.375
=4×0.375
=1.5(吨);
答:剩下1.5吨.