why europe has 50hz (Power)
why US has 60hz
why a year has 12 month
but Sept 7 is 9th month
but oct 8 is 10th month
why nove 9 is the 11th month
why deci 10 is the 12th month
5 vs 6
5 pointed start
6 pointed start
what is the base of this math
5er
6er