at the concert, seated tickets cost M and standing tickets cost N. The seated tickets are three times the price of a standing ticket. If 200 seating tickets are sold and 100 standing tickets and the total receipts from the concert is $2100, find the price of seated ticket.

Answer 1

m=3n

200 m + 100 n = 2100

so
200(3n) + 100 n = 2100
700 n = 2100
n = 3
so m = 3n = 9