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

### Instruction:
A convenience store sold 100 bags of chips in a month. In the first week, 15 bags of chips were sold. In the second week, thrice as many bags of chips were sold. There was an equal number of chips sold in the third and fourth week. How many chips was each sold in the third and fourth week?

### Response:
 Katika wiki ya pili, mifuko 15 x 3 = <<15*3=45>>45 ya chips ilinunuliwa. Jumla ya mifuko ya chips iliyonunuliwa katika wiki ya kwanza na ya pili ilikuwa 15 + 45 = <<15+45=60>>60. Hivyo katika wiki ya tatu na ya nne, mifuko 100 - 60 = <<100-60=40>>40 ya chips ilinunuliwa. Hivyo, mifuko 40/2 = <<40/2=20>>20 ya chips ilinunuliwa katika wiki ya tatu na ya nne.