Question

What is the error percentage if a number which was supposed to be divided by 3/5 was multiplied by 3/5 instead?
1. 48 percent
2. 56 percent
3. 120 percent
4. 64 percent

Answer 1

Correct Answer - Option 4 : 64 percent

Let the number be x

As, It was supposed to be divided by \( {\ {3} \over5}\)

So, x ÷ \( {\ {3} \over5}\) = x × \( {\ {5} \over3}\)= \( {\ {5x} \over3}\)

But, it was multiplied by \( {\ {3} \over5}\)

So, x × \( {\ {3} \over5}\) = \( {\ {3x } \over5}\)

Difference = \( {\ {5x} \over3}\) - \( {\ {3x } \over5}\) = \( {\ {25x - 9x} \over15}\) = \( {\ {16x} \over15}\)

% Error = \( {\ {16x} \over15}\) ÷ \( {\ {5x} \over3}\) × 100 = 64 %

Hence, "64 percent" is the correct answer.