CLAT 2015

W, X, Y and Z are four friends, who do not mind exchanging items. X has two chessboards each costing Rs. 500, and a record player. Z originally had a cycle and a walkman. Each cricket bat costs Rs. 700. Both W and Z got a cricket bat from Y. X gave his record player costing Rs. 2000 to Y. Z get a camera costing Rs. 1500 from W. The cycle of z costs Rs. 1000 and the walkman are for Rs. 700. Y had three cricket bats at the beginning and W had two cameras the total cost of which is Rs. 5000. X gave one of his chessboards to Z and took Z’s cycle. Z gave his walkman to W.

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 from one or two people who already possess the same. These people are called his/her “sources”. If the person has two sources, then he/she compares
the answer-keys obtained for 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 answer 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. This data represents question numbers.