mylist <- list(a = 3, b = c(2,8), c = c(1,4))
sumit<-function(v){x<-v$a + v$b + v$c}
x<-sumit(mylist)

sumit<-function(v){
  x<-v$a + v$b + v$c
  if (v$c ==1) x<-x*100
  }
x<-sumit(mylist)