Question

If aliens from a remote star conquer the US, then they will establish their rule over Europe also.
If Europe is subjugated then they will rule over the world.
The aliens have actually attacked mankind but have not conquered the world yet. Which of the following conclusions can be drawn from these statements?
1. The aliens have not attacked US yet.
2. The aliens have not established their rule over Europe.
3. The aliens have not conquered US so far.
4. The aliens have been defeated by the joint effort of the US and the European nations. Select the correct code:

• A. Only 1 and 2
• B. Only 2 and 3
• C. Only 4
• D. Only 3 and 4

Answer 1

The correct option is B Only 2 and 3

In this problem, the parts of the conditional statements may be labeled as follows:
X: Aliens from a remote star conquer USA.
Y: They (aliens) will establish their rule over Europe also.
Z: Europe is subjugated
Q: They (aliens) will rule over the world.
The third statement clarifies that aliens have attacked mankind but have not conquered the world yet. In other words, Q is not true at this time. The consequent in the second statement being false, then its antecedent Z must be false. For the first statement, this implies that consequent Y is false. Hence, the antecedent of the first statement, that is X must be false. This implies that II and III must be true. Hence, (b) is the answer choice.