Time: $01$h: $38$ m

and SET $(S)$ commands, and undefinen you log in to a system, no variables are defined. The course of your program will define variables via the READ $($R$)$

KILL $($K$)$ command. Notice that commands can be abbreviated to one letter.

The other way a variable can be define string and numeric. A variable may be defined via a READ command, in which case it is automatically a string

The syntax for the SET command is:

S argl, arg$2....$argx

The statement

S VAR$=$ExP

replaces $($or defines$)$ the variable VAR with the value of the expression EXP. The data type of VAR is determined by the expression.

If I execute the following code

R Z S X $Z,Y=x$

what type of variables are $x,Y$ and $Z?$

All numeric

$x$ numeric; $Y,Z$ string

$x$ numeric; $Y,Z$ undefined

Can't tell without more information

$x,Y$ numeric; $Z$ string

All string