To transport a pile of coal, 25% of this ton of coal was transported for the first time, 45% of this ton of coal was transported for the first time, and ()% of this ton of coal was transported for two times, with ()% remaining

To transport a pile of coal, 25% of this ton of coal was transported for the first time, 45% of this ton of coal was transported for the first time, and ()% of this ton of coal was transported for two times, with ()% remaining

1、25%+45%=70%
2. 1-70% = 30% left