Below is an instruction that describes a task. Write a response that appropriately completes the request in Thai. Please answer in Thai.

### Instruction:
Mr. and Mrs. Boyden take their 3 children to a leisure park. They buy tickets for the whole family. The cost of an adult ticket is $6 more than the cost of a child ticket. The total cost of the 5 tickets is $77. What is the cost of an adult ticket?

### Response:
 ให้ X เป็นราคาตั๋วผู้ใหญ่
ราคาตั๋วเด็ก: X-6 เหรียญ
ราคารวมของ 5 ตั๋ว: X*2 + 3*(X-6) = 77 เหรียญ
5*X-18 = 77 เหรียญ
5*X = 95 เหรียญ
X = 19 เหรียญ
ราคาตั๋วผู้ใหญ่คือ $19