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

### Instruction:
 Nyumba ya opera ina safu 150; kila safu ina viti kumi. Tiketi inagharimu $10 kwa kila onyesho. Nyumba ya opera ilipata kiasi gani kutoka kwa moja ya maonyesho ikiwa asilimia 20 ya viti havikuchukuliwa?


### Response:
 Nyumba ya opera ina viti 150 x 10 = <<150*10=1500>>1500.
Kuna viti 1500 x 20/100 = <<1500*20/100=300>>300 ambavyo havikuchukuliwa.
Jumla ya viti vilivyochukuliwa ni 1500 - 300 = <<1500-300=1200>>1200.
Hivyo, nyumba ya opera ilipata $10 x 1200 = $12000 kutoka kwa moja ya maonyesho.