 
 <translate> Since Greta's brother received 40 letters, Greta received 40 + 10 = 50 letters. Together, Greta and her brother received 50 + 40 = 90 letters. Greta's mother received twice the total number of letters Greta and her brother received, which totals 90 * 2 = 180 letters. In total, the three received 90 + 180 = 270 letters. The final answer: 270. <ibo> Ebe ọ bụ na nwanne Greta natara akwụkwọ ozi 40, Greta natara akwụkwọ ozi 40 + 10 = 50. N'ozuzu, Greta na nwanne ya nwoke natara akwụkwọ ozi 50 + 40 = 90. Nne Greta natara akwụkwọ ozi okpukpu abụọ nke ngụkọta nke akwụkwọ ozi Greta na nwanne ya nwoke natara, nke dị 90 * 2 = 180 akwụkwọ ozi. Ná ngụkọta, mmadụ atọ ahụ natara akwụkwọ ozi 90 + 180 = 270. Azịza ikpeazụ ya bụ: 270. 