CAT 1993 — DILR Question 5
Refer to the following information and answer the questions that follow.
“Kya – Kya” is an island in the South Pacific. The inhabitants of “Kya – Kya” always answer any question with two sentences, one of which is always true and the other always false.
You find that your boat is stolen. You question three inhabitants of the island and they reply as follows:
John says, “I didn’t do it. Mathew didn’t do it.”
Mathew says. “I didn’t do it. Krishna didn’t do it.”
Krishna says. “I didn’t do it. I don’t know who did it.”
Who stole your boat?
Answer & solution
- A
John
Mathew
- C
Krishna
- D
None of them
The best way to solve these kinds of questions is to assume that one of the statements is either true or false and thus figure out whether there is consistency in what everyone is saying.
Let us assume that John’s first statement is true. So his second statement must be false. This implies that Mathew did it. This makes Mathew’s first statement false. So the second statement has to be true. This implies that Krishna didn’t do it. So Krishna’s first statement is true and his second statement is false. Since all the statements are consistent with each other, the assumption made by us should be the correct one. So it is Mathew who stole the boat.