百分之几用英语可以说成 "percent"，这个词来源于拉丁语 "per centum"，意思是"每百"。例如：

The discount is 10 percent off. (折扣是百分之十折。)

The inflation rate is 3 percent this year. (今年的通货膨胀率是百分之三。)

The population of the city has increased by 2 percent. (该市的人口增长了百分之二。)

另外，百分之几还可以用符号"%"表示，例如：

The discount is 10% off. (折扣是百分之十折。)

The inflation rate is 3% this year. (今年的通货膨胀率是百分之三。)

The population of the city has increased by 2%. (该市的人口增长了百分之二。)

希望这些回答能帮到您！