Logical Deduction: Practice Set 1

Explanation:

From the given statement, we can infer that:

1. If Senorita is not sick, she is careless. So, AD is logically correct.

2. If Senorita is sick, she is not careless. So, CB is also logically correct.

Similarly, DA and BC are also logically correct.

Therefore, the correct sequences are AD, DA, BC, and CB.

Explanation:

From the given statement, we can infer that:

1. If the employees have confidence in the management, they are not hostile by nature. So, CB is logically correct.

2. If the employees are hostile by nature, they have no confidence in the management. So, AD is logically correct.

Similarly, BC and DA are also logically correct.

Therefore, the correct sequences are CB, BC, AD, and DA.

Explanation:

Clearly, CD is logically correct.

Also, we can infer that if all irresponsible parents do not shout, the children must have cavorted (If B does not happen, A must have happened). So, AB is also logically correct.

Explanation:

From the given statement, we can infer that:

1. If I read a horror story, I will have a nightmare. Option A does not specify the kind of stories I read. So, AD does not follow.

2. If I do not have a nightmare, I must not have read a horror story (If B does not happen, A must not have happened). So, CB is logically correct.

Explanation:

Only if A, then B

In this case, A is necessary but not sufficient condition for B to happen.

From the given statement, we can infer that:

1. If Rajeev did not use the internet, he must not have dreamt about spiders. So, DA is logically correct.

2. If Rajeev dreamt about spiders, he must have used the internet. So, CB is also logically correct.

Therefore, the correct sequences are CB and DA.

Explanation:

If and Only if A, then B

In this case, A is necessary and sufficient condition for B to happen.

From the given statement, we can infer that:

1. If Rajeev used the internet, he must have dreamt about spiders. So, BC is logically correct.

2. If Rajeev did not use the internet, he must not have dreamt about spiders. So, DA is logically correct.

3. If Rajeev dreamt about spiders, he must have used the internet. So, CB is also logically correct.

4. If Rajeev did not dream about spiders, he must not have used the internet. So, AD is also logically correct.

Therefore, the correct sequences are BC, CB, AD, and DA.

Explanation:

If A, then B

In this case, A is sufficient but not necessary condition for B to happen.

From the given statement, we can infer that:

1. If Rajeev used the internet, he must have dreamt about spiders. So, BC is logically correct.

2. If Rajeev did not dream about spiders, he must not have used the internet. So, AD is also logically correct.

Therefore, the correct sequences are BC and AD.

Explanation:

If A, then not B

In this case, A is sufficient but not necessary condition for non-occurrence of B.

From the given statement, we can infer that:

1. If Rajeev used the internet, he must not have dreamt about spiders. So, BA is logically correct.

2. If Rajeev dreamt about spiders, he must not have used the internet. So, CD is also logically correct.

Therefore, the correct sequences are BA and CD.

Explanation:

From the given statements, we can infer that:

1. If James heard of a tragedy, he must have lost his sleep. So, AC is logically correct.

2. If James did not lose sleep, he must not have heard of a tragedy. So, DB is also logically correct.

Explanation:

If not A, then B

In this case, the occurrence of A is sufficient but not necessary condition for B to happen.

From the given statement, we can infer that:

1. If Rajeev did not use the internet, he must have dreamt about spiders. So, DC is logically correct.

2. If Rajeev did not dream about spiders, he must have used the internet. So, AB is also logically correct.

Therefore, the correct sequences are DC and AB.