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

### Instruction:
Bob buys nose spray.  He buys 10 of them for a "buy one get one free" promotion.  They each cost $3.  How much does he pay?

### Response:
 Bob ananunua dawa ya pua 10. Anapata 5 bure. Hivyo analipa tu kwa 5. 5*3 = <<5*3=15>>15 dola.