$1.$ What is the output of the following commands? Try to predict the solutions before

you type in the commands. We define:

x $<-$ c$(5,2,1,4)$; xx $<-$ c$(1,10,15,18)$; y $<-$ rev$(10$:$15)$;

yy $<-$ seq$($length $=10,$ from $=9,$ by $=2)$

z $<-$ c$($TRUE$,$ FALSE, TRUE, TRUE$)$; w $<-$ c$("$Marie$",$ "Betty", "Peter"$)$;

v $<-$ c$("$I$",$ "list", "key", "standard", "attraction"$)$

$($a$)$

order$($x$)$

sum$($x$)$

range$($x$)$

length$($y$)$

sum$($yy$)$

$($b$)$

c$($xx$,$ yy$,12)$

$($c$)$

xx $-$ x

c$($x$,12)*$ y

$1$:$6+1$

$1$:$9+1$:$2$

log$($xx$)$

$($d$)$

x $<=2$

$($x $<2)$ & z

x $<(2$ & z$)$

$($x $==1)+2$

$($e$)$

substring$($w$,2,4)$

paste$($substring$($w$,1,2),$ substring$($w$,5,5),$ sep $="..")$

paste$($substring$($v$,1,2),$ collapse $="")$

$($f$)$

rbind$($x$,$xx$)$

cbind$(2,6$:$1,$ rep$($c$(3,1,4),2),$ seq$(1,1\mathrm{.}6,$ by $=0\mathrm{.}05)$