How many blood groups present in human being??
They are further broken down to: O-positive: 38 percent O-negative: 7 percent A-positive: 34 percent A-negative: 6 percent B-positive: 9 percent B-negative: 2 percent AB-positive: 3 percent AB-negative: 1 percent
4 types.....A,B,AB,O....These are again classified into A+,A-.....like that.