Quinary (base-5 or pental) is a numeral system with five as the base. A possible origination of a quinary system is that there are five fingers on either hand.
base 15
base 15 is a positional numeral system with fifteen as its base. It uses 15 different digits for representing numbers. The digits for base 15 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, and e.