Adult tickets for a play cost $19 and child tickets cost $17. If there were 36 people at a performance and the theatre collected $646 from ticket sales, how many children attended the play?

Answer 1

A. Using algebra
Let
A=number of adults who attended, then
36-A = number of children who attended
19A + 17(36-A) = 646
Solve for A.

B. Using arithmetic
If only adults went, ticket sales would have collected 36*19=$684
For every child who went, sales would reduce by $2.
So number of children=(684-646)/2=19

Answer 2

19