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

### Instruction:
Betty is saving money for a new wallet which costs $100. Betty has only half of the money she needs. Her parents decided to give her $15 for that purpose, and her grandparents twice as much as her parents. How much more money does Betty need to buy the wallet?

### Response:
 เบตตี้มีเพียง 100 / 2 = $<<100/2=50>>50.
ปู่ย่าของเบตตี้ให้เธอ $15 * 2 = $<<15*2=30>>30.
รวมกันเบตตี้มีเงินทั้งหมด $50 + $30 + $15 = $<<50+30+15=95>>95.
นั่นหมายความว่าเธอต้องการเงินเพิ่มอีก $100 - $95 = $<<100-95=5>>5.