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

### Instruction:
 Stefan anaenda kwenye mgahawa kula chakula cha jioni na familia yake. Wanaweka oda ya kitafunwa ambacho kina gharama ya $10 na vyakula vikuu 4 ambavyo kila kimoja kina gharama ya $20. Ikiwa wanaacha asilimia 20 ya jumla kama bahasha kwa mhudumu, ni kiasi gani cha pesa wanachotumia kwenye mgahawa?


### Response:
 Gharama jumla ya vyakula vikuu ni 4 * $20 = $<<4*20=80>>80.
Gharama jumla ya chakula cha jioni ni $80 + $10 = $<<80+10=90>>90.
Bahasha ni $90 * 0.20 = $<<90*0.20=18>>18
Gharama jumla na bahasha ni $90 + $18 = $<<90+18=108>>108