神马作文网两道英文数学题,很简单
来源：学生作业帮 编辑：神马作文网作业帮 分类：英语作业 时间：2024/11/11 00:46:38
两道英文数学题,很简单
我不知道我的理解对不,所以想看看大家的过程和结果和我一样不
1.In a school, of the students are girls. A year later, the number of girls in the school is increased by and the number of boys is increased by . Find the percentage increase in the total number of students.
2.The marked price of a watch is 40% above its cost. If the watch is sold at a discount of 30%, find the percentage gain or loss.
我不知道我的理解对不,所以想看看大家的过程和结果和我一样不
1.In a school, of the students are girls. A year later, the number of girls in the school is increased by and the number of boys is increased by . Find the percentage increase in the total number of students.
2.The marked price of a watch is 40% above its cost. If the watch is sold at a discount of 30%, find the percentage gain or loss.
1、在一所学校里,女生占学生总数的(?).一年后,这所学校的女生的数量增加了(?),同时男生的数量增加了(?).请问学生总数的增幅是多少?
题目没有给出数值（上边的?处）,如果以xyz表示上述缺少的数值,可以确定计算式.
没原来学生总数为a,则女生数量为ax,男生数量为a(1-x)；一年后女生数量为ax(1+y),男生数量为a(1-x)(1+z),则一年后总人数为a[x(1+y)+(1-x)(1+z)],学生总数的增幅为x(1+y)+(1-x)(1+z),代入数值即可.
2、一款手表的销售价高于其成本40%.如果这款手表在销售时给出30%的折扣,那么是赚了还是亏了?
设手表的成本是x,则销售价是x(1+40%),出售时有30%的折扣,则成交价是x(1+40%)(1-30%)=98%x,即亏了2%.
题目没有给出数值（上边的?处）,如果以xyz表示上述缺少的数值,可以确定计算式.
没原来学生总数为a,则女生数量为ax,男生数量为a(1-x)；一年后女生数量为ax(1+y),男生数量为a(1-x)(1+z),则一年后总人数为a[x(1+y)+(1-x)(1+z)],学生总数的增幅为x(1+y)+(1-x)(1+z),代入数值即可.
2、一款手表的销售价高于其成本40%.如果这款手表在销售时给出30%的折扣,那么是赚了还是亏了?
设手表的成本是x,则销售价是x(1+40%),出售时有30%的折扣,则成交价是x(1+40%)(1-30%)=98%x,即亏了2%.