1. Tardigrade
  2. Question
  3. Mathematics
  4. If n(A) = 115, n(B) = 326, n(A - B) = 47, then n(A ∪ B) is equal to

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. If $n(A) = 115$, $n(B) = 326$, $n(A - B) = 47$, then $n(A \, \cup \,B)$ is equal to

Sets

Solution:

$n(A) = m(A - B) + n(A \cap B)$ implies
$115 = 47 + n ( A \cap B)$
$\therefore n(A \cap B) = 115-47 = 68$
$\therefore n(A \cup B) = n(A) + n(B) - n(A \cap B)$
$= 115 + 326-68 = 373$