7th Class Mental Ability Logical Venn Diagram Logical Venn Diagrams

Logical Venn Diagrams

Venn diagram is a pictorial representation of classes representing items and their common properties. We usually use circles to draw a Venn diagram. A Venn diagram consists of two or more circles. Circles may or may not have some common regions according as the respective classes do or do not have common properties amongst them. Note that the given statements are taken to be true disregarding commonly known facts. Let us illustrate the concept of Venn diagrams with the following examples.

EXAMPLE

1.  Which of the following figures represents the relation between 'Parrots', 'Birds' and 'Crows' ?

(a)              (b)              (c)           (d)

Explanation (b):

Parrots and crows are different from one another.

So, the Venn diagram of these two would be as follows:

Further, both parrots and crows are birds. So, the final Venn diagram is:

So, the correct option is (b).

2.  Direction (I-II): Study the diagram given below and answer the following questions based on it.

I.  What does letter D represent?

(a) Uneducated women in villages

(b) Unemployed women in villages who are not educated

(c) Educated unemployed women

(d) Educated employed women

Explanation (b):

Letter D lies inside the triangle and square only.

So, D represents unemployed women in villages.

Also, D lies outside the circle.

So, D represents uneducated women.

Hence, D represents unemployed women in villages who are not educated. So, the correct option is (b).

II.  Educated unemployed women in cities are represented by _______.

(a) E and F                    (b) D                             (c) F                              (d) G and E

Explanation (c):

Only the letter F represents educated unemployed women in cities.        

So, the correct option is (c).