Question

A group of 25 students want to see a drake concert. Tickets for members of drakes fan club cost $20 and tickets for no members cost $25. The total cost for tickets is $550

Answer 1

If you would like to know how many of each type of ticket were sold, you can calculate this using the following two equations:

a ... the number of drakes fan club tickets
s ... the number of no members tickets

$550 = a * $20 + s * $25 ... 550 = 20 * a + 25 * s
a + s = 25 ... a = 25 - s
__________________
550 = 20 * a + 25 * s

550 = 20 * (25 - s) + 25 * s

550 = 20 * 25 - 20 * s + 25 * s

550 - 20 * 25 = 5 * s

550 - 500 = 5 * s    /5

s = 50 / 5 

s = 10 tickets

a = 25 - s = 25 - 10 = 15 tickets

Result: There were 15 drakes fan club and 10 no members tickets sold.