Mental Ability & Reasoning · Section 1
Organise information, apply rules and reach conclusions based only on what is given.
Section 1
This section checks whether you can take a set of facts and rules, organise them, and work out what must, could or cannot be true. PPSC calls this structuring unorganised information: you pick out the facts that matter, ignore the ones that do not, and arrange them in a form you can work with.
The questions are set in office situations: files reviewed in order, officers assigned to desks, duty rosters, seating at a meeting, and policy rules of the "if this, then that" kind. You do not need any outside knowledge. Every answer comes from the information in the question.
Question types you will meet
Topic by topic
1.1
Separate what must be true (true in every allowed arrangement) from what could be true (true in at least one) and what cannot be true. Turn every rule into shorthand at once: A < B for "A before B", [AB] for "B immediately after A", A → B for "if A, then B".
1.2
Draw one numbered slot for each position, write the fixed items in first, and note restrictions underneath. "A before B" means A cannot be last and B cannot be first; chains such as A < B < C remove even more positions.
1.3
Know whether everyone must go into a group (a split) or only some are chosen (a selection). "A and B are apart" forces them into opposite groups in a split, but in a selection both may simply be left out. Group sizes are strong clues.
1.4
Ordering with labels: instead of "third" you say "Wednesday". Build a calendar grid, place the activity with the fewest possible days first, and when two cases remain, follow each one through.
1.5
People in a row, around a table or on floors. Get direction right ("left" depends on which way people face). Around a table there is no first seat, so fix one person and place the others relative to them.
1.6
From "If P then Q" only two moves are valid: P gives Q, and not-Q gives not-P. Q does not prove P, and not-P proves nothing. "P only if Q", "No P without Q" and "Not P unless Q" all mean P → Q.
1.7
A conclusion is valid only if it cannot be false when the statements are true. "No A are B" and "Some A are B" can be reversed; "All A are B" cannot. Draw circles for all, some and no.
1.8
For number series, check a constant difference, changing differences, a constant ratio, squares, alternating steps and two woven series, in that order. For codes, pair the letters by position. Memorise A=1, E=5, J=10, O=15, T=20, Y=25.
Good habits
Common traps
Try them first
Answer each question yourself, then open the explanation to check your method. The samples from PPSC's official guidebook show the real style of the test.
The word BORED is coded as FNBLK. How will ROBED be written in the same code?
Answer: B. BNFLK
Exam tip: Eliminate quickly: R=B means the answer must begin with B, leaving just two options.
An office manager is assigning four officers (W, X, Y and Z) to two desks, with exactly two officers per desk. W and X cannot be at the same desk. If Y is at Desk 1, Z must be at Desk 2. If Z is at Desk 1, which pair must be at Desk 2?
Answer: D. Cannot be determined without more information
A process has five stages: 1. Receive application; 2. Verify documents; 3. Obtain approval; 4. Record decision; 5. Notify applicant. Verification must come immediately after receipt. Approval must come before the decision is recorded. Notification must come after the decision is recorded. Which sequence is valid?
Answer: A. 1 – 2 – 3 – 4 – 5
All department heads attend the monthly management meeting. Some employees who attend the meeting are not department heads. Which statement is necessarily true?
Answer: B. All department heads attend the meeting.
Exam tip: A restatement of a given fact can be the correct answer.
Five reports (P, Q, R, S and T) are submitted one a day, Monday to Friday. R is submitted on Wednesday. P is submitted on the day immediately before Q. T is submitted on a later day than S. On which day can P be submitted?
Answer: C. Monday or Thursday
Exam tip: Place the fixed item first, then the block: it has the fewest possible positions.
Rule: "No grant is released without the Director's signature." The grant for the Okara office has been released. What follows?
Answer: A. The Director signed the Okara grant.
Exam tip: "No P without Q" is the same as "If P, then Q".
What comes next in the series 3, 7, 15, 31, 63, ...?
Answer: D. 127
Exam tip: The differences (4, 8, 16, 32) double each time, which points to a × 2 rule.
No contract staff sign cheques. Some clerks are contract staff. Which statement must be true?
Answer: B. Some clerks do not sign cheques.
Exam tip: "Some A are B" plus "No B are C" gives "Some A are not C".
PPSC Mental Ability Test Series
Timed quizzes on this section only, with your score and every answer explained after you submit. For a quiz that mixes all four sections, see the trial quiz and full mixed tests.
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CSS Nexus Mental Ability and Reasoning Workbook (PDF)
554 pages covering all four sections: lessons, 367 solved examples, 794 practice questions with answer keys, and a timed test for each section.
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