Maths : Basic Numeracy

Q 75 / 370

UPSC CSE Prelims 2024

A number is mistakenly divided by 4 instead of multiplying by 4. What the percentage change in the result due to this mistake?

EXPLANATION

Correct Option

Let the original number be represented by 'x'.

  • The actual intended result of the operation was 4 multiplied by the number, which is 4x.
  • The mistaken result, due to division by 4, is x/4.
  • To determine the change in the result, the difference between the actual and mistaken results is calculated: 4x−x4=16x−x4=15x4
  • The percentage change is calculated relative to the actual intended result: ChangeActual Result×100=15x44x×100 =15x16x×100=1516×100=0.9375×100=93.75%

Therefore, the percentage change in the result due to the mistake is 93.75%.

Incorrect Options

Options 1 (25%), 2 (72.75%), and 3 (50%) are incorrect as they do not correspond to the accurate calculation of the percentage change based on the given problem statement. The correct calculation, as demonstrated above, yields 93.75%.