Function using ifelse not returning a vector in R

I wrote a somewhat grotesque function, which should simply return a vector with two values.

For example, if you put in 33, you should get back c(30, 40). It couldn't get much simpler than this.

return_a_range <- function(number){
    ans <-  ifelse(  (30  <= number & number <= 40), c(30, 40),
                     (ifelse( (40  < number  & number  <= 50), c(40, 50),
                              (ifelse( (50  < number  & number  <= 60), c(50, 60),
                                       (ifelse( (60  < number  & number  <= 70), c(60, 70),
                                                (ifelse( (70  < number  & number  <= 80), c(70, 80),
                                                         (ifelse( (80  < number  & number  <= 100), c(80, 100),                      
                                                                           ans <- c("NA"))))))))))))
    return(ans)}

return_a_range(33)

Why is this returning only 30? How am I not getting back c(30, 40)? Why did R decide to only return the value in the first position of the vector?