If in a certain code language 'pen pencil' is written as$\text{'}\$ \pounds \text{'}$',eraser sharpener' is written as$@ \#\text{'}$, and 'pencil eraser' is written as '$\$ @$',then what is the code for 'pen'?

 Pen pencil$=\$\pounds$ .   ......(i) 

Eraser sharpner $= @\#$ ........(ii)

 Pencil eraser$= \$@$ ...........(iii) 

From (i) and (iii), the code for 'pencil' is $\$$.

Hence, from (i), the code for 'pen' is $\pounds$