Probando el documento
sample(5:20,10,replace=FALSE)
## [1] 5 10 19 6 16 8 12 7 13 20
sample(70:80,size= 20,replace = TRUE)
## [1] 74 75 72 71 79 78 80 71 74 74 70 74 78 79 77 75 73 78 78 77