Step by Step please

Question

The school that Perry goes to is selling tickets to a choral performance. On the first day of ticket sales the school sold 13 senior citizen tickets and 12 child tickets for a total of $227. The school took in $40 on the second day by selling 1 senior citizen ticket and 3 child tickets. Find the price of a senior citizen ticket and the price of a child ticket.

Answer 1

$13 for a senior ticket

$9 for a child ticket

13(13) +12(9) = 169 + 108 = 277

1(13) +3(9) = 13+27 = 40

that's the correct solution. It works

below is another attempt to solve the problem, but with a mistake(s) somewhere

13s +12c = 227

1s +3c = 40

multiply by 4

4s +12c = 160 subtract from 1st equation to get

13s -4s = 227 -160

9s = 67

s = 67/9 = the number of senior tickets

c = (40-67/9)/3 = (360-67)/27 = 293/27 = number of child tickets

must be a mistake somewhere as the number of tickets should be an integer

not a fraction