Paper I · 9 Logical Reasoning & Analytical Ability · 9.4 Ratio, ages, averages and mixtures

9.4.6 Variation: direct, inverse and joint; mean and third proportional

"y varies as x" means y = kx for a fixed k; find k from the one case given, then use it for the case asked. Inverse, joint and square-root variation only change the formula, not the method.

  • APPSC Paper I · Paper I
  • Standard level
  • 7 min read
  • Full course

Key terms

  • variation
  • direct proportion
  • inverse proportion
  • joint variation
  • constant of variation
  • partly fixed partly varying
  • mean proportional
  • third proportional
  • fourth proportional
  • continued proportion

What this note covers

  1. Core factsFoundation
  2. ExplainedStandard
  3. DeeperAdvanced
  4. Common trapsFoundation
  5. Quick revisionFoundation

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