This problem contains a question and two statements labelled I and II giving certain data. You have to select the correct answer from (A) to (D) depending on the sufficiency of the data given in the statements to answer the question.
Who among Arun, Bhargav and Chadda is the most efficient?
I. To complete a work, Chadda takes 5 times as much time as Arun and Bhargav take working together.
II. To complete a work Arun takes as much time as Bhargav and Chadda take working together.

If the question can be answered by using one of the statements alone but cannot be answered by using the other statement alone.

Statements:

I. To complete a work, Chadda takes 5 times as much time as Arun and Bhargav take working together.

=> This implies that the time taken by Chadda (C) is 5 times the time taken by Arun and Bhargav together (A + B). So, C = 5(A + B).

II. To complete a work, Arun takes as much time as Bhargav and Chadda take working together.

=> This implies that the time taken by Arun (A) is equal to the time taken by Bhargav and Chadda together (B + C). So, A = B + C.

Now, we can conclude from II:

A = B+C

If the efficiency of A is 1 then we can conclude that the efficiency of B or C can not be more then A.

So, it is clear from the statement II, that Arun(A) is more efficient.

and, there no possible way to find out the most efficient one from statement I.

Thus, Option (I) If the question can be answered by using one of the statements alone but cannot be answered by using the other statement alone is correct.