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

### Instruction:
 Matias ni muuzaji katika duka la vitabu. Alinunua vitabu 7 Jumanne na mara tatu zaidi Jumatano. Ikiwa mauzo ya Jumatano yalikuwa mara tatu zaidi Alhamisi, Matias aliuza vitabu vingapi katika siku hizo tatu jumla?


### Response:
 Jumanne, Matias aliuza vitabu 7.
Jumatano, Matias aliuza 3*7 = <<3*7=21>>21 vitabu.
Alhamisi, Matias aliuza 3*21 = <<3*21=63>>63 vitabu.
Matias aliuza 7+21+63 = <<7+21+63=91>>91 vitabu katika siku hizo tatu.