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

### Instruction:
A cake of 400 grams is divided into eight equal parts. Nathalie eats one-eighth of the cake, and Pierre eats double what Nathalie ate. How much did Pierre eat, in grams?

### Response:
 Nathalie alikula 1/8 * 400g = <<1/8*400=50>>50g ya keki.
Pierre anakula 2 * 50g = <<2*50=100>>100g ya keki.