The little Town Fine Arts Center charges $21 per adult and $10 per senior citizen for its performances. on a recent weekend evening when 559 people paid admission, the receipts were $7493. How many who paid were senior citizens?

1 Answer
Nov 8, 2016

386 were senior citizens

Explanation:

Let a be the number of adult paid admissions
and s be the number of senior paid admissions.

We are told
[1]XXXa+s=559
and
[2XXX21a+10s=7493

We could rearrange [1] as
[3]XXXs=559a

Then substituting (559a) for s in [2]
[4]XXX21a+559010a=7493

[5]XXX11a=1903

[6]XXXa=173

The substituting 173 for a in [3]
[7]XXXs=559173=386