Independent solution

How to solve this Inclusion-Exclusion question

Setup

Setup

Let A, B, and C denote the three listed home-feature sets.

A=130,B=280,C=150|A|=130,\qquad |B|=280,\qquad |C|=150

Model

Model

Apply three-set inclusion-exclusion using inclusive pair intersections.

ABC=A+B+CABACBC+ABC|A\cup B\cup C|=|A|+|B|+|C|-|A\cap B|-|A\cap C|-|B\cap C|+|A\cap B\cap C|

Compute

Compute

Evaluate the union and take its complement in the portfolio.

ABC=130+280+150403050+10=450|A\cup B\cup C|=130+280+150-40-30-50+10=450
1000450=5501000-450=550

Answer

Answer

There are 550 policies with none of the three features.

550(D)\boxed{550\quad\text{(D)}}