Help me figure it out.?

Question

At an exhibition,th number of male visitors was 500 more than the number of female visitors on the first day.On the second day,the number of male visitors decreased by 10% but the number of female visitors increased by 15%.Given that there were 1680 visitors on the second day,how many female visitors were there on the second day?

Answer 1

let 'm' be the number of males on the first day

let 'f' be the number of females on the first day

f+500=m

.9m+1.15f=1680

.9(f+500)+1.15f=1680

2.05f+450=1680

2.05f=1230

f=600

If you needed to find the number of males just substitute f=600 into f+500=m, but you don't need to for this question.