Aptitude - Percentage - Discussion
Discussion Forum : Percentage - General Questions (Q.No. 9)
9.
| A student multiplied a number by | 3 | instead of | 5 | . |
| 5 | 3 |
What is the percentage error in the calculation?
Answer: Option
Explanation:
Let the number be x.
| Then, error = | 5 | x - | 3 | x = | 16 | x. |
| 3 | 5 | 15 |
| Error% = |  |
16x | x | 3 | x 100 |  % = 64%. |
| 15 | 5x |
Discussion:
134 comments Page 10 of 14.
Harish said:
6 years ago
Assume the number to be multiplied as 30.
The actual value is (5/3*30) =50.
But his value is (3/5*30) =18.
So the error is 32.
Here, 50 is 100% then 32 is 64%.
Therefore error is 64%.
The actual value is (5/3*30) =50.
But his value is (3/5*30) =18.
So the error is 32.
Here, 50 is 100% then 32 is 64%.
Therefore error is 64%.
Aditya said:
6 years ago
We can take 100 as a number then multiply 3/5 and 5/3 as well. U will get 60 and 166.5, then
166.5-60 = 106.5.
(106.5/166.5) * 100 = 64%.
166.5-60 = 106.5.
(106.5/166.5) * 100 = 64%.
Sanghavi said:
6 years ago
I am not getting it. Please explain me.
Linoj said:
6 years ago
Thank you @Ameer.
Anshuman said:
6 years ago
The difference between the two nos become 16/15.
Then the percentage of 16/15 in the true value 5/3 is 64%.
16/15 * 100 = 64%. @Sandhavi.
Then the percentage of 16/15 in the true value 5/3 is 64%.
16/15 * 100 = 64%. @Sandhavi.
Bishal Chakraborty said:
6 years ago
Just take LCM OF 3and 5, assume the number is 15.
So, if multiplied by 3/5 it will be 9 if by 5/3 it will be 25. So, the diff is 16.
Percentage 16/25 * 100% = 64%.
So, if multiplied by 3/5 it will be 9 if by 5/3 it will be 25. So, the diff is 16.
Percentage 16/25 * 100% = 64%.
Satish said:
6 years ago
Thanks for the explanation @Pradeep and @Jack.
Sanjay said:
6 years ago
How did 16 come?
Satyam said:
6 years ago
Thanks @Pradip.
Anirudh said:
5 years ago
Error = true value - false value.
Percentage of x = x*100 / true value.
Percentage of x = x*100 / true value.
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