Paul M. answered • 06/20/18

BS Mathematics, MD

Let F be the number of $5 tickets and T the number of $10 tickets.

F + T = 23

5F + 10T = 175

Divide the second equation by 5.

F + T = 23

F + 2T = 35

Subtract the first equation from the second

T = 12 and then since F + T = 23, F = 11