A complex number can be visually represented as a pair of numbers (a, b) forming a vector on a diagram called an Argand diagram, representing the complex plane. Re is the real axis, Im is the imaginary axis, and i is the imaginary unit which satisfies i2 = â1.
When discussing blood types, the two groupings most commonly used are the ABO (A, B, AB, O) and Rh (+, -) systems. The least common blood type in humans is Bombay (EXTREMELY râ¦are), which is a type O with missing H antigen. Otherwise, of the normal ABO and Rh typings, the least common group is AB-.
The most common blood group in New Zealand is O+.    According to the Neww Zealand Blood Service the frequency of blood groups in the New Zealand donor population is: â¦   O+ 38%  A+ 32%  O- 9%  B+ 9%  A- 6%  AB+ 3%  B- 2%  AB- 1% . 6 people found this useful.