CAT 2020 Slot 2 DILR Question & Solution

Logical ReasoningMedium

Data Set

The Humanities department of a college is planning to organize eight seminars, one for each of the eight doctoral students - A, B, C, D, E, F, G and H. Four of them are from Economics, three from Sociology and one from Anthropology department. Each student is guided by one among P, Q, R, S and T. Two students are guided by each of P, R and T, while one student is guided by each of Q and S. Each student is guided by a guide belonging to their department. Each seminar is to be scheduled in one of four consecutive 30-minute slots starting at 9:00 am, 9:30 am, 10:00 am and 10:30 am on the same day. More than one seminars can be scheduled in a slot, provided the guide is free. Only three rooms are available and hence at the most three seminars can be scheduled in a slot. Students who are guided by the same guide must be scheduled in consecutive slots.

The following additional facts are also known.

1. Seminars by students from Economics are scheduled in each of the four slots.
2. A’s is the only seminar that is scheduled at 10:00 am. A is guided by R.
3. F is an Anthropology student whose seminar is scheduled at 10:30 am.
4. The seminar of a Sociology student is scheduled at 9:00 am.
5. B and G are both Sociology students, whose seminars are scheduled in the same slot. The seminar of an Economics student, who is guided by T, is also scheduled in the same slot.
6. P, who is guiding both B and C, has students scheduled in the first two slots.
7. A and G are scheduled in two consecutive slots.

Question 1

Which one of the following statements is true?

Two seminars are scheduled in the first slot.

Only one seminar is scheduled in the second slot.

Three seminars are scheduled in the first slot.

Three seminars are scheduled in the last slot.

Solution:

Let's look at all the students we have A,B,C,D,E,F,G,H. The guides are P,Q,R,S,T and they mentor 2,1,2,1,2 students respectively.

Slots are 9:00,9:30,10:00,10:30 . Moreover economics, sociology and anthropology have 4,3,1 students respectively.

Now from 5th statement, two sociology seminars and economics seminars are held in the same slot. This will not take place at 10:00(only one seminar is scheduled at 10:00), this will also not take place at 10:30( An anthropology seminar is scheduled at 10:30 and maximum three seminars are scheduled in a slot. Hence this will happen at either 9 or 9:30. Now from (7) A and G are scheduled in consecutive slots. A is scheduled at 10:00. Hence G will be scheduled at 9:30. SO from (5), there will be three students having their seminars at 9:30.

Combining this data with the remaining points we get the following table

Moreover we do know that students having same subject are scheduled in consecutive slots. So we get

Here we can see that two seminars are scheduled in first slot.

Question 2

Who all are NOT guiding any Economics students?

Q, R and S

P, Q and R

P, R and S

P, Q and S

Solution:

Let's look at all the students we have A,B,C,D,E,F,G,H. The guides are P,Q,R,S,T and they mentor 2,1,2,1,2 students respectively.

Slots are 9:00,9:30,10:00,10:30 . Moreover economics, sociology and anthropology have 4,3,1 students respectively.

Combining this data with the remaining points we get the following table

Moreover we do know that students having same subject are scheduled in consecutive slots. So we get

As we can see from the above table, P,Q and S are not guiding any economics student

Question 3

Which of the following statements is necessarily true?

Q is guiding G.

H is an Economics student.

S is guiding F.

B is scheduled in the first slot.

Solution:

As we can clearly say from here that H/D/E are all economics students. Hence Option B is definitely correct

Question 4

If D is scheduled in a slot later than Q's, then which of the following two statement(s) is(are) true?
(i) E and H are guided by T.
(ii) G is guided by Q.

Only (ii)

Neither (i) nor (ii)

Only (i)

Both (i) and (ii)

Solution:

Now D is scheduled in a slot later than Q. Q can mentor only F or G, but obviously he can't mentor F because F is in the last slot, hence Q will mentor G. In that scenario D has to take the 10:30 slot which means D will be mentored by R and E/H will be mentored by T. So statement 1 and statement 2 both are correct.

Question 5

If E and Q are both scheduled in the same slot, then which of the following statements BEST describes the relationship between D, H, and T?

Exactly one of D and H is guided by T.

Both D and H are guided by T.

At least one of D and H is guided by T.

Neither D nor H is guided by T.

Solution:

If E and Q are scheduled in the same slot, they both can be in the last slot. In that case E will be guided by R and both D and H will be guided by T. Moreover if they are in the second slot, E will be guided by T and atleast one of D and H will be guided by T. Hence option (c) is correct

Question 6

If D is scheduled in the slot immediately before Q’s, then which of the following is NOT necessarily true?

G is guided by Q.

E is guided by R.

F is guided by S.

D is guided by T.

Solution:

Now D is scheduled in the slot immediately before Q. In that case Q will be in the 9:30 slot and D will be in the 9:00 am slot. Hence D will be mentored by T and one of E/H will be mentored by R and the other by T. Obviously E is guided by R is not necessarily true as he can be mentored by T also.