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

### Instruction:
 Duka la wanyama lina mbwa 2 na paka kadhaa. Mbwa mmoja gharama $20, na paka gharama $15. Ikiwa hisa ina thamani ya $100, duka la wanyama lina paka wangapi?


### Response:
 Acha x iwe idadi ya paka.
2*20 + 15*x = 100
40 + 15*x = 100
15*x = 60
x = <<4=4>>4 paka