Question

If n(A) = 110, n(B) = 300, n(A - B) = 50, then n(A U B) equals​

Answer 1

Answer:

n(A U B) = 350

Step-by-step explanation:

Given:

n(A) = 110

n(B) = 300,

n(A - B) = 50

Using important results:

n(A - B) = n(A) - n(A ∩B)

Put in the Values

50 = 110 - n(A ∩B)

-60 = - n(A ∩B)

n(A ∩B) = 60

Now using this formula

n(A U B) = n(A) + n(B) - n(A ∩ B)

Put in the values

n(A U B) = 110 + 300 - 60

n(A ∩B) = 350

Answer 350

$\rule{200}{1}$

Results used:

Condition is that A, b , C needs to be finite.

✴ n(A U B) = n(A) + n(B) - n(A ∩ B)

✴n(A - B) = n(A) - n(A ∩B)