Question
If n(A) = 20, n(B) = 28 and n(A ∪ B) = 36, then n(A ∩ B) = ?
✓
Answer
n(A ∪ B) = n(A) + n(B) – n(A ∩ B)
∴ 36 = 20 + 28 – n(A ∩ B)
∴ n(A ∩ B) = 20 + 28 – 36
∴ n(A ∩ B) = 12
∴ 36 = 20 + 28 – n(A ∩ B)
∴ n(A ∩ B) = 20 + 28 – 36
∴ n(A ∩ B) = 12
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Write the value of $\sqrt[3]{125\times27}.$
→Find the following ratios $:$ The ratio of diagonal of a square to its side, if the length of side is $7\ cm.$
→Prove the Theorem : If a pair of alternate angles formed by a transversal of two lines is congruent then the two lines are parallel.
Factorise:
$2 x^4-32$
→$2 x^4-32$
Rationalise the denominator of the following:$\frac{4}{\sqrt{11}-\sqrt{7}}$
→The curved surface area of a cone is $2200$ sq.cm and its slant height is $50\ cm.$ Find the total surface area of cone.$\left(\pi=\frac{22}{7}\right)$
Given: Length $(l) = 50\ cm,$ curved surface area of cone $= 2200$ sq.cm
To find: Total surface area of the cone
→Given: Length $(l) = 50\ cm,$ curved surface area of cone $= 2200$ sq.cm
To find: Total surface area of the cone
Factorise:
$(3 a-2 b)^3+(2 b-5 c)^3+(5 c-3 a)^3$
→$(3 a-2 b)^3+(2 b-5 c)^3+(5 c-3 a)^3$
In figure, write all pairs of adjacent angles and all the linear pairs.
If x = 3k + 2 and y = 2k - 1 is a solution of the equation 4x - 3y + 1 = 0, find the value of k.
Find the value of a for which $(x+1)$ is a factor of $\left(a x^3+x^2-2 x+4 a-9\right)$.
→