- There is a lot of interest in the first five ranks for Class XI students. One student guessed the rank order as Ankita, Bhagyashree, Chanchal, Devroopa and Esha. Later upon announcement of the results, it was found that not only did he get each student out off her true position, none of the students in his ranking correctly followed her immediate predecessor. Another student guessed Devroopa, Ankita, Esha, Chanchal and Bhagyashree. Even his guess was wrong. It was found that he had got two positions correct, and two students in his ranking correctly followed their immediate predecessors.
Which of the following is true about the correct rank order?
a)Devroopa got the first position
b)Esha got the fourth position
c)Bhagyashree got the fourth position
d)Chanchal got the second position
e)Ankita got the third position
Explanation
SOLUTION-[ E ]
It is given that A – 1, B – 2, C – 3,D – 4 and E – 5 is wrong. The rank of none of the student matched and no student followed her immediate predecessor.
D – 1, A – 2, E – 3, C – G, B – 5 has two correct and two students correctly followed the predecessor. The two conditions can be satisfied when either 1 and 2 or 4 and 5 are correct rankers and one of these two pairs is the one which correctly followed the predecessor. The other one which correctly followed the predecessor should be one from the other three.
Case (i), D – 1, A – Z are correct ranks. In this case C – 4 or B – 5 correctly followed the predecessor apart form A – Z. Then the possible correct arrangements are:
D – 1 D – 1
A – 2 A – 2
B – 3 or C – 3
E – 4 B – 4
C – 5 E – 5
(a) (b)
Here in (b) C – 3 and E – 5 are same as the guess made by the first student in which all are wrong. Hence, (b) is eliminated. In case (a) B is following A as in the guess made by the first student. Hence (a) is also eliminated.
case (ii): C – 4, B – 5 are correct ranks.
In this case A – 2 or E – 3 correctly followed the predecessor apart form B – 5. Then the possible correct arrangements are
A – 1 E – 1
E – 2 D –2
D – 3 A – 3
C – 4 or C – 4
B – 5 B – 5
(c) (d)
In (c) A – 1 is matching with the guess of the first student. Hence, (c) is eliminated. Arrangement (d) satisfied all the conditions. Hence, it is true that Ankit got the third position.
