Slot Method

Definition

Slot Method in plain English

Reach for the Slot Method on sequential decisions with simple position-isolated restrictions. Clues include first digit must be odd, last cannot be zero, or positions filled independently. Draw slots (_ _ _ _), fill the most restricted slot first, then the rest. Listing full strings explodes; slots multiply local choices in order. The order of filling matters only for bookkeeping: restricted first prevents illegal options from ever entering a later blank. Micro-example: 3-digit codes with first digit odd (1,3,5,7,9) and no zero in the last place. First slot has 5 choices, middle has 10, last has 9, so 5 x 10 x 9 = 450 codes without writing a single full string.

Related GMAT terms

• Harmonic Mean
• Complement Rule
• Standard Double-Matrix
• Linear Multi-Count Equation
• Complement Extreme Shortcut
• Slicing Isolated Pools
• Isolated Element Identity
• Glue-Block Permutation
• Total Minus Unwanted
• Descending Anchor Heuristic