Instructions

In each question below are given two statements followed by four conclusions numbered I, II, III and IV. You have to take the two given statements to be true even if they seem to be at variance from commonly known facts. Read all the conclusions and then decide which of the given conclusions logically follow from the two given statements disregarding commonly known facts.

Question 94

# Statements:1. All books are magazines.2. All newspapers are magazines.Conclusions :I. Some magazines are books.II. Some magazines are newspapers.III. Every magazine is either book or newspaper.IV. All magazines are book as well as newspapers

Solution

Possible valid conclusions from 'All books are magazines' are: 'All books are magazines, and vice versa', 'All books are magazines, but not vice versa'.

Possible valid conclusions from 'All newspapers are magazines' are: 'All newspapers are magazines, and vice versa', 'All newspapers are magazines, but not vice versa'.

The aim now is to eliminate options by finding a combination of possible conclusions that invalidate the said option.

1) This is true in each of the cases laid down in 'All books are magazines'.

2) The same logic used for the first option, and hence a valid conclusion.

3) This may not be the case, as there is no statement to indicate that each of the elements in 'magazine' has been covered by either a book or newspaper. What if magazine is a way bigger set and 'books/newspaper' form very small sets of the same?

4) Again, it is possible that magazine is a way bigger set and 'books/newspaper' form very small sets of the same. Hence, an invalid conclusion.