Multiple choice

If the price of coal be raised by $20$% find by how much percent a housewife must reduce her consumption of that article so as not to increase her expenditure.

  1. $40$%
  2. $16\dfrac {2}{3}$%
  3. $10$%
  4. $33\dfrac {1}{3}$%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If price increases by 20% (1/5), the consumption must decrease by 1/(1+5) = 1/6. 1/6 is 16.66% or 16 2/3%.

AI explanation

Using the formula for percentage reduction in consumption to maintain expenditure, (R / (100 + R)) * 100, where R is the 20% price hike. Substitute 20 into the formula to get (20 / 120) * 100, which equals 50 / 3 or 16 2/3%. The housewife must reduce her consumption by 16 2/3%.

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