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

### Instruction:
 Addilynn alikwenda dukani na kununua mayai sita kwa kila dazeni kwa matumizi nyumbani kwake. Baada ya wiki mbili, alitumia nusu ya mayai, kisha kwa bahati mbaya akavunja mayai 15 yaliyosalia wakati akisafisha rafu. Mayai mangapi yamesalia kwenye rafu?


### Response:
 Kwa kuwa dazeni ina mayai 12, idadi ya jumla ya mayai ambayo Addilynn alinunua ni 12*6 = <<12*6=72>>72 mayai.
Ikiwa alitumia nusu ya mayai, idadi ya mayai yaliyosalia ni 72/2 = <<72/2=36>>36 mayai.
Wakati akisafisha rafu, alivunja mayai 15, kubaki mayai 36-15 = <<36-15=21>>21 mayai.