A jazz concert brought in ​$168,500 on the sale of 8,100 tickets. If the tickets sold for$15 and $25 each, how many of each type of ticket were​ sold?

Answer 1

15x + 25(8100 - x) = 168500

15x + 202500 - 25x = 168500

-10x = -34000

x = 3400

3400 @ $15, 4700 @ $25

Answer 2

Let a = number of $15 tickets

b = number of $25 tickets

then,

a + b = 8100

and 15a + 25b = 168500 then b = 6740 - .6a

so,

a + 6740 - .6a = 8100 or .4a = 1360 or

a = 3400 ($15 tickets)

b = 4700 ($25 tickets)