Question

1.某班女生人数占总人数的6/13,后来有4名女同学转走,现在女生人数占全班的5/12,全班现有多少人?

Answer 1

1 (6/13x-4)/(x-4)=5/12 x=52 现有48人

2 a/(15+a)=1/4 a=5L 5b/(11-5)=62.5% b=0.75L

3 0.4a+0.1b=0.3(a+b)

0.3(a+b)+0.2*300=0.25(a+b+300)

a=200

4 总数3/2a+a+5/3a=25/6a

金牌3/2 / 25/6 =9/25=36%

银牌6/25=24% 铜牌 2/5=40%

5 a(1+20%)=b(a+15%)-11.2

a=b(1-10%)

a=144