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

### Instruction:
Kate wants to buy a special pen as a gift for her friend. The pen costs $30, and Kate only has money for a third of that amount. How much more money does she need to buy the pen?

### Response:
 ณ ขณะนี้ เคทมีเพียง 1/3 ของราคาปากกา ดังนั้นเคทต้องการเงินเพิ่มอีก 30 - 10 = $<<30-10=20>>20 เพื่อซื้อปากกา.