Sub Contraries I and O Both can be true together but not false together
Contraries A and E Both cannot be true together but can be false together
For mediates:
A+ A= A A+ E= E
E + A= O Reverse
E+ I= O Reverse
I + A= I
I + E= O
1 If the statement ‘all students are intelligent’ is true, which of the following statements are false?
(i) No students are intelligent.
(ii) Some students are intelligent.
(iii) Some students are not intelligent.
(A) (i) and (ii)
(B) (i) and (iii)
(C) (ii) and (iii)
(D) (i) only
Answer B
2 Two statements I and II given below are followed by two conclusions (a) and (b). Supposing the statements are true, which of the following conclusions can logically follow ?
Statements:
I. Some flowers are red.
II. Some flowers are blue.
Conclusions:
(a) Some flowers are neither red nor blue.
(b) Some flowers are both red and blue.
(A) Only (a) follows.
(B) Only (b) follows.
(C) Both (a) and (b) follow.
(D) Neither (a) nor (b) follows
Answer D
June 2010
Two statements I and II given below are followed by two conclusions (a) and (b). Supposing the statements are true, which of the following conclusions can logically follow?
I. Some religious people are morally good.
II. Some religious people are rational.
Conclusions:
(b) Non-rational religious persons are not morally good.
(A) Only (a) follows.
(B) Only (b) follows.
(C) Both (a) and (b) follow.
(D) Neither (a) nor (b) follows.
Answer D
June 2011
If the statement ‘some men are cruel’ is false, which of the following statements/statement are/is true ?
(i) All men are cruel.
(ii) No men are cruel.
(iii) Some men are not cruel.
(A) (i) and (iii)
(B) (i) and (ii)
(C) (ii) and (iii)
(D) (iii) only
Answer C
December 2011
If the proposition “Vegetarians are not meat eaters” is false, then which of the following inferences is correct? Choose from the codes given below:
1. “Some vegetarians are meat eaters” is true.
2. “All vegetarians are meat eaters” is doubtful.
3. “Some vegetarians are not meat eaters” is true.
4. “Some vegetarians are not meat eaters” is doubtful.
Codes:
(A) 1, 2 and 3
(B) 2, 3 and 4
(C) 1, 3 and 4
(D) 1, 2 and 4
Answer A
June 2012
Venn diagram is a kind of diagram to
(A) represent and assess the validity of elementary inferences of syllogistic form.
(C) represent and assess the truth of elementary inferences of syllogistic form.
(D) assess but not represent the truth of elementary inferences of syllogistic form
Answer A प्रतिनिधित्व और syllogistic रूप के प्राथमिक निष्कर्षों की वैधता का आकलन।
If the proposition “All men are not mortal” is true then which of the following inferences is correct ? Choose from the code given below :
1. “All men are mortal” is true.
2. “Some men are mortal” is false.
3. “No men are mortal” is doubtful.
4. “All men are mortal” is false.
Code :
(A) 1, 2 and 3
(B) 2, 3 and 4
(C) 1, 3 and 4
(D) 1 and 3
Answer B
