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Time & Work
· History📜 History & Discovery
Work-rate problems appear in the Chinese "Nine Chapters on the Mathematical Art" (~200 BCE) and Indian texts like Aryabhata's Aryabhatiya (499 CE). Medieval European guilds used such calculations to estimate labour costs. Arab mathematician Al-Khwarizmi formalised the algebraic treatment in the 9th century.
⚡ 2026 Update
In 2026 the LCM Method has become the default for TCS NQT and CAT prep — it eliminates fractions by setting total work equal to the LCM of all the timings, so every per-day output is a clean integer. Faster than the rate method on every alternating-day variant.