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

### Instruction:
 Darasani, kuna viti vya bluu, viti vya kijani, na viti vya nyeupe. Kuna viti vya bluu 10. Viti vya kijani ni mara tatu ya viti vya bluu, na kuna viti vya nyeupe 13 chini ya idadi ya viti vya kijani na bluu pamoja. Kuna viti vingapi darasani?


### Response:
 Kuna viti vya kijani 10 x 3 = <<10*3=30>>30.
Jumla ya viti vya bluu na kijani ni 10 + 30 = <<10+30=40>>40.
Hivyo, kuna viti vya nyeupe 40 - 13 = 27.
Hivyo, kuna jumla ya viti 40 + 27 = <<40+27=67>>67 darasani.