Meredith works at a blood bank. She needs to write a report of the ratio of type-A blood donated to type-O blood donated, but she lost this month's logs that had the quantities. She knows that last month 25 pints of type-A blood were donated and 42 pints of type-O blood were donated. She remembers that this month 55 pints of type-A blood were donated. If the ratio held true for this month, how can Meredith determine the amount of type-O blood donated?