Arithmetic Ability
Percentage

156 / 161

Q.

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

View Answer

Correct choice: B

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 %
156 / 161