If the numerator of fraction is increased by and denominator

2020

If the numerator of a fraction is increased by 25% and the denominator is decreased by 20%, the new value is 5/4. What is the original value?

  1. A.

    3/5

  2. B.

    4/5

  3. C.

    7/8

  4. D.

    3/7

Attempted by 199 students.

Show answer & explanation

Correct answer: B

Key idea: Represent the original fraction as n/d and apply the percentage changes.

  • New numerator = 1.25n = 5n/4.

  • New denominator = 0.80d = 4d/5.

  • New fraction = (5n/4)/(4d/5) = 25n/(16d) = 5/4.

  • So n/d = (5/4) × (16/25) = 4/5.

Answer: Option 1, 4/5, is correct.

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