Scheduling and Categorisation Puzzles
Scheduling and Categorisation Puzzles
Scheduling puzzles place people on days of a week or months of a year; categorisation puzzles match each person with a profession, colour or subject. Both are solved in a grid: days or names down the side, attributes across, ticking what is fixed and crossing what is ruled out. Each clue removes options until one arrangement is left.
1. Method Box
| Puzzle | Grid | Useful facts |
|---|---|---|
| Days of a week | Monday to Sunday as slots 1 to 7 | "Two days after Thursday" is Saturday |
| Months | Month order Jan to Dec | 31-day months: Jan, Mar, May, Jul, Aug, Oct, Dec; 30-day: Apr, Jun, Sep, Nov; Feb 28 or 29 |
| Day and subject | Days down, people and subjects across | Fix the day of each subject first if given |
| Categorisation | People down, professions and colours across | One tick per row and per column |
A negative clue ("A is not the doctor") becomes powerful once only two options remain
If a clue links two attributes ("the teacher likes green"), keep it as a pair until the person is known
✗ "K's exam is two days after M's (Thursday)" means Friday | ✓ Two days after Thursday is Saturday
✗ June has 31 days | ✓ June has 30 days; the 30-day months are April, June, September and November
हिंदी नोट: समय-सारणी पहेली में दिन या महीने को क्रम से लिखिए, और वर्गीकरण पहेली में व्यक्ति × गुण की तालिका बनाकर सही पर ✓ और गलत पर ✗ लगाइए। 30 दिन वाले महीने: अप्रैल, जून, सितंबर, नवंबर।
Exam Pointer: Verified NTPC patterns: seven people with exams on different days of a week (March 2026 Graduate CBT-1) and five friends matched to professions and colours or traits (March 2016 CBT-1, June 2022 CBT-2). Month and day-plus-subject puzzles had no verified NTPC shift and are tagged syllabus-based.
Pariksha Pattern: Every Way NTPC Asks This Topic
Pattern 1: Days of a week
[PYQ: NTPC Graduate CBT-1 22-Mar-2026 Shift-2]
Seven people J to P each have an exam on a different day from Monday to Sunday of one week (Monday = day 1). M's exam is on Thursday. K's exam is two days after M's. J's exam is before M's, on an even-numbered day. N's exam is on the day immediately before J's. L's exam is on the last day of the week. P's exam is on a day next to K's.
EXAM LEVEL
Q. Whose exam is on Friday?
M Thursday, K Saturday, L Sunday. P is next to K: Friday (Sunday is taken).
Answer: P
EXAMATLAS LEVEL
Q. Using the same clues, how many exams fall between O's and K's, and who has the exam on Monday?
J is on an even day before Thursday: Tuesday. N is the day before: Monday. O takes the remaining Wednesday. Between Wednesday (O) and Saturday (K) are M and P.
Answer: 2; N
Pattern 2: Months of a year
[Pattern: syllabus-based, PYQ-style]
Six people F to K each visit in a different one of these months of one year: January, March, April, June, August and November. J visits in March. H's month has 30 days and comes after J's. F visits in the month immediately after H's in this list. K visits in the last of the listed months. G's month has 31 days. I visits before G.
EXAM LEVEL
Q. Who visits in June?
K takes November. H has a 30-day month after March: April or June. If H were June, F would be August, and G (31 days) would need January with I before it, impossible. So H is April and F June.
Answer: F
EXAMATLAS LEVEL
Q. Using the same clues, who visits in August, and how many people visit between I and F?
G needs a 31-day month: January or August. I must come before G, so G is August and I January. Order: I (Jan), J (Mar), H (Apr), F (Jun), G (Aug), K (Nov). Between I and F are J and H.
Answer: G; 2
Pattern 3: Matching people with professions and colours
[PYQ: NTPC CBT-1 30-Mar-2016 Shift-3 | NTPC CBT-2 16-Jun-2022 Shift-1]
Five friends A to E are a doctor, a teacher, an engineer, a lawyer and a pilot, and each likes a different colour: red, blue, green, white and black. A is neither the doctor nor the teacher. The teacher likes green. C is the pilot. B likes blue and is neither the doctor nor the lawyer. The doctor likes white. E is not the doctor. A likes black. The pilot does not like white or green.
EXAM LEVEL
Q. Who is the doctor?
The doctor is not A, not B, not C (pilot) and not E, so D is the doctor and likes white.
Answer: D
EXAMATLAS LEVEL
Q. Using the same clues, what is A's profession, and which colour does the pilot like?
B likes blue, so B is not the teacher (green); B is not the doctor or lawyer, so B is the engineer. A is not the doctor or teacher, and pilot and engineer are taken: A is the lawyer. E is the teacher and likes green. The colour left for C, the pilot, is red.
Answer: Lawyer; red
Pattern 4: Day and subject together
[Pattern: syllabus-based, PYQ-style]
W, X, Y and Z each give one lecture from Monday to Thursday, on Maths, Physics, Chemistry and Biology (one each). The Chemistry lecture is on Wednesday. X's lecture is the day after the Chemistry lecture. X does not teach Maths. W teaches Physics, and W's lecture is before Y's. Maths is on Monday. Z does not teach Biology.
EXAM LEVEL
Q. Who teaches Chemistry?
X lectures on Thursday, so Thursday's subject is Physics or Biology; W teaches Physics, so X teaches Biology. Monday is Maths, which W (Physics) cannot give. If Y lectured on Monday, W could not be before Y. So Z gives Maths on Monday, W Physics on Tuesday and Y Chemistry on Wednesday.
Answer: Y
EXAMATLAS LEVEL
Q. Using the same clues, on which day does W lecture, and what does X teach?
From the arrangement: Monday Z (Maths), Tuesday W (Physics), Wednesday Y (Chemistry), Thursday X (Biology).
Answer: Tuesday; Biology
60-Second Revision
- Draw the slots (days, months) or a person × attribute grid.
- Count days carefully: two days after Thursday is Saturday.
- Know the 30-day months: April, June, September, November.
- Use paired clues ("the teacher likes green") once one side is known.
Next Step: Puzzles done. Solve one floor, day or matching puzzle a day in the ExamAtlas RRB NTPC 2026 mock tests; the grid you draw in the first 20 seconds answers every question in the set.