practice_problems/problems/unit-01/D-unions-intersections-and-complements/3

[giscus[bot]]

practice_problems/problems/unit-01/D-unions-intersections-and-complements/3

https://mids-w203.github.io/practice_problems/problems/unit-01/D-unions-intersections-and-complements/3.html

[dcaponi]

I think you can also get here by applying compliment rule to A' and B' on the left hand side

$P(A' \cap B') = (1 - P(A))(1- P(B))$
FOIL from algebra
$1 - P(B) - P(A) + P(A)P(B)$
But we know $P(A)P(B)$ aka $P(A \cap B)$ isn't possible because A and B are disjoint so that's just 0
1 - 0.3 - 0.5 = 0.2