Bissoy.com
Doctors Medicines MCQs Q&A

If A ∩ B = A then A ∪ B is equal to ?

If A ∩ B = A then A ∪ B is equal to ? Correct Answer B

Concept:

Union of the sets: 

Union of two given sets is the set that contains those elements that are either in A or in B, or in both.

The  union of the sets A and B, denoted by A U B

[ alt="F2 A.K Madhu 05.06.20 D2" src="//storage.googleapis.com/tb-img/production/20/06/F2_A.K_Madhu_05.06.20_D2.png" style="width: 161px; height: 108px;">

 

Intersection of Sets:

The intersection of two given sets is the largest set which contains all the elements that are common to both the sets.

The intersection of Sets A and B, denoted by A ∩ B

[ alt="F2 A.K Madhu 05.06.20 D3" src="//storage.googleapis.com/tb-img/production/20/06/F2_A.K_Madhu_05.06.20_D3.png" style="width: 161px; height: 108px;">

 

Formula:  A ∪ B = A + B - A ∩ B

 

Calculation:

Given: A ∩ B = A

To Find: A ∪ B

As we know, 

A ∪ B = A + B - A ∩ B

⇒ A ∪ B = A + B - A

∴ A ∪ B = B

Related Questions

Which of the following statements are true relating to payment of equal pay for equal work both for men and women?
1. ILO adopted equal remuneration Convention No. 100 in 1951.
2. India ratified ILO's Equal Remuneration Convention No. 100 in the year 1956.
3. Provisions relating to equal pay for equal work for both men and women are provided under Article 42 of the Indian Constitution.
4. The Equal Remuneration Ordinance was promulgated on 26th September, 1975.
Two metallic balls when completely immersed in water have equal upthrust on them, then which statement is correct: a) Both balls must have equal weights b) Both balls must have equal densities c) Both balls must have an equal volume
“What is the different between height and radius of solid cylinder?” Which of the following option is sufficient alone to find the answer? A) A solid cylinder is made by melting a solid sphere. The radius of cylinder is 3 times the radius of a circle whose area is 154 sq.m. Height of cylinder is equal to the height of cone whose volume is 2772 cubic meters. B) Area of a rectangle whose longer side is ¾ times the radius of a solid cylinder, is 168 sq.m and, Volume of solid cylinder is 2772 cubic meters and its height is 18 m. C) A metallic cone of radius 15m and height 35m is melted into the solid cylinder of radius equal to the radius of a circle whose area is equal to the area of rectangle whose sides are in the ratio 4 : 3 respectively. D) The curved surface area of the solid cylinder is 3 time the surface area of a sphere of radius 7m and height of cylinder is equal to the height of a metallic cone whose curved surface area is 308 sq.m. 
There is a rhombus of side 6 cm. One of the diagonal of the rhombus is equal to the side of the rhombus. An isosceles triangle is formed whose two equal sides are equal to another diagonal of the rhombus and the third side is equal to 8 cm. Find the area of the triangle.
Necessary condition for obtaining an interference pattern when light waves (of same frequency) from two points S1 and S2 superpose is:   Intensity of two waves Phase difference between the two waves at S1 and S2 must be 1) Must be equal Zero 2) Must be equal π  3) Must be equal Constant with time but not necessarily zero 4) Need not be equal Constant with time but not necessarily zero
Among the following propositions two are related in such a way that one is the denial of the other. Which are those propositions ? Select the correct code : Propositions : (a) All women are equal to men (b) Some women are equal to men (c) Some women are not equal to men (d) No women are equal to men
Two right angled triangles are congruent if :
I. The hypotenuse of one triangle is equal to the hypotenuse of the other.
II. A side for one triangle is equal to the corresponding side of the other.
III. Sides of the triangles are equal.
IV. An angle of the triangle are equal.
Of these statements, the correct ones are combination of:
Marginal cost is equal to marginal revenue, average cost is equal to average revenue, average revenue is equal to marginal revenue and average cost is equal to marginal cost. This is the condition of
1. long period equilibrium for a firm under monopoly
2. short period equilibrium for a firm under oligopoly
3. long period equilibrium
4. long period equilibrium for a firm under perfect competitions
Select the correct answer
The marginal cost is equal is to marginal revenue, the average cost is equal to average revenue, average revenue is equal to marginal revenue, and the average cost is equal to marginal cost. This is the condition of
1. Long-period equilibrium for a firm under monopoly.
2. Short-period equilibrium for a firm under oligopoly.
3. Long-period equilibrium
4. Long-period equilibrium for a firm under perfect competition.
In perfect competition, when a firm is in short periods, for equilibrium, the following condition does apply
1. Marginal cost must equal marginal revenue.
2. Average cost must equal average revenue.
3. Marginal revenue must equal average revenue.
4. Marginal cost must equal average cost.