His Abs

The blood group of 30 students of class IX are recorded as follows.A,B,B,B,O,B,B,A,A,B,A,O,AB,O AB,AB,B,AB,B,A,O,AB,B,A,O,A,B,A,A,AB. .(a) Make a frequency distribution table for the above data. (b)Mr 'X' meets an accident and needs blood, His blood group is AB. How many of these students are universal Donars and how many are universal Receipent.

His secretary and his typist ...... on leave today. (is/are)

A male child colour blind and his blood group is 'AB' Identify the parents from the following pairs :