The total subsets of a set with n elements is 2^{n} Since this set has 5 elements, the total number of its subsets is 2^{5} = 32.
Legend: e = pencil ; o=book ; a=paper ; b=ballpen ; w=workbook
Subsets:
{e} , {o} , {a} , {b} , {w}
{e,o} , {e,a} , {e,b} , {e,w} , {o,a} ,{o,b} , {o,w} , {a,b} ,{a,w} ,{b,w}
{e,o,a} , {e,o,b} , {e,o,w} , {e,a,w} , {e,a,b} , {e,b,w} , {o, a,b} , {o,a,w} , {o,b,w} , {a,b,w}
{e,o,a,b} , {e,o,a,w} , {o,a,b,w} , {e,o,b,w} , {e,a,b,w}
{ } , {e,o,a,b,w}
