Question

A student was asked to multiply a number by 5/3.He multiplied it by 3/5 instead.Find the percentage error in tue calculation​

Answer 1

Answer:

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 value) * 100

             = [(16/15) * x/(5/3) * x] * 100

             = 64 %