Question

Both Mrs. Smith and Mrs. Jones had babies the same day in the same hospital. Mrs. Smith took home a baby girl, whom she named Shirley.
Mrs. Jones took home a baby girl, whom she named Jane. Mrs. Jones began to suspect, however, that her child had been accidentally switched
with the Smith baby in the nursery. Blood tests were made; Mr. Smith was type A, Mrs. Smith was type B, Mr. Jones was type A, Mrs. Jones was
type A, Shirley was type O, and Jane was type B. Had a mix-up occurred?

Answer 1

Yes , mix up has occurred because Shirley could be A B AB or O but jane be A or O not B !