Are the numbers three or seven in folktales?

Both have spirtual angles- the three degrees of craftsman: Apprentice, Journeyman, and Master, for example, the three states of Matter- Solid-Liquid-Gas, The three tenses of time- past, present and future, and also the Religious angles of Faith , Hope and Charity and so on.. some Fairy Tales and even science-fictionized fantasies have added on the 72 hour time limit to perform some usually bizarre task- this is in a sense a sickening parody of the Passion Of Christ- and the three day interval between Good Friday and Easter Sunday! It figures in too many tales to be coincidental. as for 7, Seven days of the week, 7 sacraments, 7 days of creation, 7Th day adventism, and so on. there is a lot of sneaky parodying of religion in these tales and it is not, methinks, a good ideal.