Probando el documento
sample(5:20,10,replace = FALSE)
## [1] 16 15 20 17 19 14 11 8 5 12
sample(70:80, size = 20,replace = TRUE)
## [1] 71 77 78 80 76 78 77 80 70 71 79 73 80 75 79 80 76 75 76 70