The Venn diagram shows three sets P, Q and R. Use set notation to describe the shaded part.

The shaded region consists of two distinct parts:

• The part where sets P and Q overlap, but set R does not.
• The part where sets P and R overlap, but set Q does not.

• The region where P and Q overlap is $P \cap Q$. If R does not overlap, we exclude R, which is $R'$. So this part is $P \cap Q \cap R'$.
• The region where P and R overlap is $P \cap R$. If Q does not overlap, we exclude Q, which is $Q'$. So this part is $P \cap R \cap Q'$.

Since the shaded area includes both of these parts, we use the union ($\cup$) operator:

We can factor out P from the expression:

The expression $(Q \cap R') \cup (R \cap Q')$ represents the symmetric difference between sets Q and R, often denoted as $Q \Delta R$.
Therefore, the shaded region can also be described as:

The final answer is $\boxed{(P \cap Q \cap R') \cup (P \cap R \cap Q')}$ or $\boxed{P \cap (Q \Delta R)}$.