What is the percentage error in calculation A student multiplied a number by 3/5 instead of 5 3?

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Given:

A boy multiplied a number 3/5 instead of 5/3

Formula used:

Percentage error = Difference of numbers/Required number

Calculation:

Let the number be 15 (L.C.M. of 5 and 3)

Wrong number = 15 × 3/5 = 9

Required number = 15 × 5/3 = 25

Percentage error = [(25 – 9)/25] × 100 = (16/25) × 100 = 64%

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1050

Q:

Answer:   B) 64 %

Explanation:

Let the number be x.

Then, ideally he should have multiplied by  x by 5/3. Hence Correct result was x * (5/3)= 5x/3. 

By mistake he multiplied x by 3/5 . Hence the result with error  = 3x/5 

Then, error = (5x/3 - 3x/5) = 16x/15 

Error %  = (error/True vaue) * 100 = [(16/15) * x/(5/3) * x] * 100 = 64 %

Subject: Percentage - Quantitative Aptitude - Arithmetic Ability

A student multiplied a number by 315 instead of 5 / 3 . what is the percentage error in the question.

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