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

### Instruction:
The difference in age between Declan's elder son and younger son is 10 years. If the elder son is 40 years old now, how old will the younger son be 30 years from now?

### Response:
 Ikiwa mtoto mkubwa ana umri wa miaka 40, mtoto mdogo ana umri wa miaka 40-10 = <<40-10=30>>30.
Miaka 30 kutoka sasa, mtoto mdogo atakuwa na umri wa miaka 30+30 = <<30+30=60>>60.