Vedadots
Q4950/80Q51
Q50·CSAT · Prelims 2022

Data sufficiency for scheduling sequential events

DI / DSPuzzlesFactual singleMedium

Question

Six lectures A, B, C, D, E and F, each of one hour duration, are scheduled between 8:00 a.m. and 2:00 p.m. Consider the Question and two Statements given below: Question: Which lecture is in the third period? Statement-1: Lecture F is preceded by A and followed by C. Statement-2: There is no lecture after lecture B. Which one of the following is correct in respect of the Question and the Statements?

Options

a

Statement-1 alone is sufficient to answer the Question

b

Statement-2 alone is sufficient to answer the Question

c

Both Statement-1 and Statement-2 are sufficient to answer the Question

d

Both Statement-1 and Statement-2 are not sufficient to answer the Question

Answer

Explanation

Set up a grid with 6 available periods (1 to 6).

Statement 1 provides a strict, contiguous 3-block sequence: `A - F - C`. This block can slide anywhere across the 6 periods. Insufficient.

Statement 2 locks lecture B into the absolute final slot: `B` is at Period 6. Insufficient.

Combine both statements: We have 5 remaining slots (Periods 1 to 5) to fit the `A - F - C` contiguous block, along with the two floating lectures `D` and `E`. Let's test valid placements for the `A - F - C` block:

Case 1: Placed at 1-2-3. The 3rd period is C.
Case 2: Placed at 2-3-4. The 3rd period is F.
Case 3: Placed at 3-4-5. The 3rd period is A.

Because the 3rd period changes depending entirely on where the rigid sequence slides, no unique answer can be found.

In scheduling block puzzles, if a contiguous rigid block is shorter than the available open runway slots, the target index will float, resulting in data insufficiency.

Answer: (d).

Question details

Year

2022

Paper

CSAT

Question

Q50

Section

Data Interpretation & Sufficiency

Sub-topic

Puzzles

Type

Factual single

Difficulty

Medium

Source hint

Six lectures scheduling, which is 3rd period?

See all questions on Puzzles

Browse every tagged question across all years

Explore →