Question

Calculate the number of proper subsets6,11,10,15

Answer 1

A proper subset B of A is a set such that all elements in B are elements in A, but A has atleast one element that is not in B.

So if
\[A = \left \{ 6, 10, 11, 15 \right \} \]

Then
\[\left \{ 6 \right \} \]

is a proper subset, and
\[\left \{ 6,11 \right \} \]
\[\left \{ 10,15 \right \} \]

Can you list all subsets then?