Probando el documento
sample(5:20,10,replace =FALSE)
## [1] 5 20 17 13 8 19 15 10 6 11
sample(70:80,size = 20,replace = TRUE)
## [1] 78 77 78 80 79 78 79 79 78 71 76 73 73 77 80 74 76 79 77 79