CAT DILR Questions | CAT Analytical Reasoning questions
Comprehension
Directions for Questions: Study the information below and answer questions based on it.
Recently, the answers of a test held nationwide were leaked to a group of unscrupulous people. The investigative agency has arrested the mastermind and nine other people A, B, C, D, E, F, G, H and I in this matter. Interrogating them, the following facts have been obtained regarding their operation. Initially the mastermind obtains the correct answer-key. All the others create their answer - key in the following manner. They obtain the answer key from one or two people who already possess the same. The people are called his/her “sources”. If the person has two sources, then he/she compares the answer-keys obtained form both sources. If the key to a question from both sources is identical, it is copied, otherwise it is left blank. If the person has only one source, he/she copies the source’s answers into his/her copy. Finally, each person compulsorily replaces one of the answers (not a blank one) with a wrong answer in his/her answer key.
The paper contained 200 questions; so the investigative agency has ruled out the possibility of two or more of them introducing wrong answers to the same question. The investigative agency has a copy of the correct answer key and has tabulated the following data. These data represent question numbers.
CAT/2003
Question . 209
How many people (excluding the mastermind) needed to make answer - keys before C could make his answer-key?
Explanatory Answer
Method of solving this CAT DILR Question from Analytical Reasoning question
(c) C has 2 wrong answers and 3 blank answers. This means one wrong answer has been done by himself and the other from the source, say S, from where he copied. 3 blank answer mean that they were present in S’s answer key too. This means S has got it from two sources – S2 , one with one wrong answer and the other S3 , with 2 wrong answers. The one haveing 1 wrong answer could have got it from the master mind but the other one has to get it from a single source S1 , ( who has got it from MM) with one wrong answer. So, 4 people before him
