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

### Instruction:
Charlotte needs to know how much money to have with her when she goes to the shoe store. How much money should Charlotte bring to buy a pair of boots, if the original price is $90 and there is a discount of 20%?

### Response:
 จำนวนส่วนลดคือ 90 x 0.2 = $<<90*0.2=18>>18
จำนวนเงินที่ต้องจ่ายหลังหักส่วนลดคือ 90 – 18 = $<<90-18=72>>72
ชาร์ลอตต้องเอา 72 ดอลลาร์