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

### Instruction:
 Alvin ana umri wa miaka 30 na Simon ana umri wa miaka 5 kutoka kuwa nusu ya umri wa Alvin. Simon ana umri gani?


### Response:
 Alvin: miaka 30
Simon: (1/2)*30-5 = <<30/2-5=10>>10 miaka