Quant · Indore LRDI

Logical Reasoning Sets (Indore QA-embedded)

3 sub-topics · 14 lessons · 74 questions · 23 PYQs

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Arrangements and Scheduling7 lessons · 49 questions · 16 PYQs

Tournaments and Games3 lessons · 13 questions · 6 PYQs

Grouping and Grid Puzzles4 lessons · 12 questions · 1 PYQs

Formula sheet

Counting with 'all A are B' and 'no A is C'
$A\subseteq B\Rightarrow |B\setminus A|=|B|-|A|;\quad A\cap C=\varnothing\Rightarrow|A\cup C|=|A|+|C|$
Landau's condition for score lists
$\text{scores }s_1\le\cdots\le s_n\text{ possible}\iff\sum_{i\le k}s_i\ge\binom{k}{2}\ \forall k,\ \sum s_i=\binom{n}{2}$
Weights on one pan
$\text{one pan: }k\text{ weights weigh up to }2^k-1\ (1,2,4,\ldots)$
Weights on both pans
$\text{both pans: }k\text{ weights weigh up to }\frac{3^k-1}{2}\ (1,3,9,\ldots)$
Wins equal losses
$\sum\text{wins}=\sum\text{losses},\qquad \sum\text{draw entries}=2\times\text{drawn matches}$
Matches in a round robin
$\text{matches in a single round robin of }n\text{ teams}=\binom{n}{2}$
Circular seatings up to rotation
$\text{circular seatings of }n\text{ people (up to rotation)}=(n-1)!$
Counting duty slots
$\text{slots to fill}=\sum_{\text{days}}\text{people needed}=\text{people}\times\text{days each}$