Playbook

Mathematical Logic

88 q - 1.92/paper - 31% HARD. The one chapter in MHT-CET Maths with its own execution mode: 70% of its stems ask which statement is true, against roughly 0% everywhere else. Its 31% HARD overstates the cost, because the difficulty is front-loaded into learning ONE technique (build the truth table) that then applies to every question.

Questions in the bank
88
q/paper (2024–25 shifts)
1.92
Tagged HARD
31%
Subtopics
3

Strand: Quick-Win

When you’ll see it

Statements, connectives and quantifiers — or a switch circuit diagram, which is the same thing drawn differently.

How this chapter is tested

88 q at 1.92 per paper and 31% HARD. This is the one chapter in MHT-CET Maths with its own execution mode: around 70% of its stems ask which of the four statements is true, against roughly 0% everywhere else in the subject. Every other chapter hands you a problem to solve; this one hands you four claims to adjudicate. That difference is worth more than any formula on this page, because it changes what you do when you read the question.

The 31% HARD figure overstates the cost, and it is worth understanding why. The difficulty here is front-loaded into learning ONE technique — build the truth table — which then applies to essentially every question in the chapter. Once that technique is automatic, a HARD logic question and a MODERATE one take about the same amount of time. Compare that with Indefinite Integration, where every new integrand is a fresh recognition problem.

Switch circuits sit inside the largest subtopic (Negation, Equivalence, Tautology, and Switch Circuits, 47 q at 36% HARD) and intimidate students who have not been told the translation. It is two rules: switches in series are AND, switches in parallel are OR. After that a circuit is a logical expression and the same truth table answers it.

The tactic follows from the execution mode. With four claims and no negative marking, building the truth table and evaluating all four options is a complete method that always terminates — and a partially built table plus elimination still beats leaving the question blank, because a blank and a wrong answer cost the same nothing.

The sub-skills

The distinct skills inside the chapter, in the order to learn them.

  • Truth tables and truth values

    Construct the table for any compound statement and read the truth value off it. 27 q at 26% HARD, and the technique that every other skill in this chapter runs on. Learn it first and learn it properly.

  • Converse, inverse, and contrapositive

    Given a conditional, write its three relatives and know that only the contrapositive is logically equivalent to it. 14 q at 21% HARD — the cheapest block in the chapter and pure pattern work.

  • Negation, equivalence, and tautology

    Negate compound statements and quantified statements, test two expressions for equivalence, and classify a statement as a tautology or a contradiction from its final column. Part of the 47 q, 36% HARD subtopic.

  • Switch circuits

    Translate a circuit into a logical expression — series is AND, parallel is OR — then simplify or test it exactly as you would any other statement. Also part of the 47 q block, and much cheaper than it looks.

Traps to expect

Distractor shapes this chapter reuses. The Traps page covers the patterns that cut across chapters.

  • Negation of a conditional written as another conditional

    Denying an implication asserts the antecedent and denies the consequent; it is not another implication. The tempting wrong option negates both parts and keeps the arrow.

  • Converse offered where the contrapositive is asked

    Only the contrapositive shares the truth value of the original. Converse and inverse are equivalent to each other and to neither, and all three appear in the option list.

  • Quantifier negated without negating the predicate

    Negating a for-all statement gives a there-exists statement whose inner claim is ALSO negated. Options that flip only the quantifier are the standard distractor.

  • Parallel branch read as an AND

    In a switch circuit, current flows if EITHER parallel branch is closed. Reading parallel as AND inverts the expression and produces a clean but wrong simplification.

Drill every mathematical logic question

88 questions from the bank, scoped to 3 bundled subtopics.

Drill one subtopic at a time

The 3 subtopics this playbook covers, in catalog order.

  • Negation, Equivalence, Tautology, and Switch CircuitsDrill
  • Truth Tables and Truth ValuesDrill
  • Converse, Inverse, and ContrapositiveDrill

Related playbooks

Often paired with this one — the technique, the trap or the taxonomy overlaps. Drill these next.