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

### Instruction:
Emily is 20 years old and her older sister, Rachel, is 24 years old.  How old is Rachel when Emily is half her age?

### Response:
 Tofauti ya umri: 24 - 20 = <<24-20=4>>4 miaka
Rachel akiwa mara mbili ya umri wa Emily, ana umri wa 4 x 2 = <<2*4=8>>8 miaka.