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

### Instruction:
Greta received 10 more letters in the mail than her brother. Greta's mother received twice the total number of letters Greta and her brother received. Calculate the total number of letters the three received if Greta's brother received 40 letters.

### Response:
 Greta alipokea barua 40+10 = <<40+10=50>>50.
Pamoja, Greta na ndugu yake walipokea barua 50 + 40 = <<50+40=90>>90.
Mama wa Greta alipokea mara mbili idadi ya barua ambazo Greta na ndugu yake walipokea, ambayo ni jumla ya 90*2 = 180 barua.
Jumla, watatu walipokea barua 90+180 = <<90+180=270>>270.