Q. Six lectures A, B, C, D, E and F, each of one hour duration, are scheduled between 8:00 a.m. and 2:00 p.m.
Consider the Question and two Statements given below:
Question : Which lecture is in the third period?
Statement-1 : Lecture F is preceded by A and followed by C.
Statcment-2 : There is no lecture after lecture B.
Which one of the following is correct in respect of the Question and the Statements?
a. Statement-1 alone is sufficient to answer the Question
b. Statement-2 alone is sufficient to answer the Question
c. Both Statement-1 and Statemcnt-2 are sufficient to answer the Question
d. Both Statement-1 and Statement-2 are not sufficient to answer the Question
Correct Answer: d. Both Statement-1 and Statement-2 are not sufficient to answer the Question
Question from UPSC Prelims 2022 CSAT Paper
Explanation :
To determine which lecture is in the third period, we will analyze the given statements:
Statement-1: Lecture F is preceded by A and followed by C.
From this statement, we know the order of three lectures: A -> F -> C. However, it does not provide any information about the exact time or period of these lectures, so we cannot determine which lecture is in the third period using this statement alone.
Statement-2: There is no lecture after lecture B.
This statement tells us that lecture B is the last lecture, scheduled at 1:00 p.m. However, it does not provide any information about the other lectures, so we cannot determine which lecture is in the third period using this statement alone.
Now, let’s see if we can answer the question by combining both statements:
From Statement-1, we know that A -> F -> C is a sequence of lectures. And from Statement-2, we know that B is the last lecture. So, we can create two possible scenarios:
Scenario 1:
A -> F -> C -> D -> E -> B
Scenario 2:
D -> A -> F -> C -> E -> B
In both scenarios, we cannot determine which lecture is in the third period, as it can be either C (Scenario 1) or F (Scenario 2). Even E position is also not fixed.
Thus, the correct answer is d. Both Statement-1 and Statement-2 are not sufficient to answer the question.
