While he was still single, Ricardo opened a savings account with his mother, Angelina. The signature card they signed stated that the account was owned by them as joint tenants with the right of survivorship. No statement as to survivorship was made on the savings account passbook. Ricardo later married Margo. On Ricardo's death, Margo claimed a share of the $58,000 account on the ground that there was no survivorship because the passbook did not mention it and because Ricardo had withdrawn substantial amounts from the account during his life. Decide who has the right to the money in the account.