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

### Instruction:
Nelly wants to buy pizza for herself and her 14 friends. Each pizza costs $12 and can feed 3 people. If Nelly earns $4 a night babysitting the neighbors' kids, how many nights will she have to babysit to afford the pizza?

### Response:
 เธอต้องซื้อพิซซ่า 15 / 3 = <<15/3=5>>5 ใบ
พิซซ่าทั้งหมดจะต้องจ่าย 5 * $12 = $<<5*12=60>>60
เนลลี่ต้องทำงานดูแลเด็ก 15 คืนเพื่อจะซื้อพิซซ่าได้