FREE CLAST Logical Reasoning Questions and Answers

Question 1

The statement "Bob is an engineer or Tom is a musician" is negated by:

Accepted Answer

Bob is not an engineer and Tom is not a musician

Answer

According to De Morgan's Laws, the negation of a disjunction ('P or Q') is the conjunction of the negations ('not P and not Q'). Therefore, the negation of 'Bob is an engineer or Tom is a musician' is 'Bob is not an engineer and Tom is not a musician'.

Question 2

"Pam is going to work and Kay is going shopping," in the negative, means:

Accepted Answer

Pam is not going to work or Kay is not going shopping

Answer

According to De Morgan's Laws, the negation of a conjunction ('P and Q') is the disjunction of the negations ('not P or not Q'). Therefore, the negation of 'Pam is going to work and Kay is going shopping' is 'Pam is not going to work or Kay is not going shopping'.

Question 3

If Kari is presented with a job offer, she will take it, the converse is true:

Accepted Answer

Kari is offered a job and she does not accept it

Answer

The original statement is a conditional: 'If Kari is presented with a job offer (P), she will take it (Q)'. The condition under which this statement is false is when the premise (P) is true, but the conclusion (Q) is false. This means 'Kari is offered a job AND she does not accept it', which is the logical negation of the conditional statement.

Question 4

The opposite of "All the staff members will attend the picnic" is:

Accepted Answer

Some employees will attend the picnic

Answer

The logical opposite (negation) of a universal affirmative statement ('All X are Y') is a particular negative statement ('Some X are not Y'). Therefore, the negation of 'All the staff members will attend the picnic' is 'Some employees will not attend the picnic'. Option D, 'Some employees will attend the picnic', is not the logical opposite as it can be true even if the original statement is false (e.g., if only half the staff attends).

Question 5

It is illogical to claim that both Frank and Ralph are students. The logical equivalent is:

Accepted Answer

Frank is not a student or Ralph is not a student

Answer

The statement 'It is illogical to claim that both Frank and Ralph are students' means that the conjunction 'Frank is a student AND Ralph is a student' is false. According to De Morgan's Laws, the negation of 'P AND Q' is 'NOT P OR NOT Q'. Thus, the logical equivalent is 'Frank is not a student OR Ralph is not a student'.

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FREE CLAST Logical Reasoning Questions and Answers