Answers

  • qais
  • Content Quality
2016-02-08T12:43:06+05:30
Let the diameter be 10 units
radius = 5 units
CSA = 4πr² = 4×π×25 = 100π sq units
now, diameter 20% decreased = 8 units
radius = 4 units
CSA' = 4πr'² = 4π× 16 = 64π sq units
difference = 100π - 64π =36π
Percentage decrease = (36π/100π)×100 = 36%
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