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 2 of 14.
Vinay said:
3 months ago
Let's assume no is 30 it is divisible by both 5 and 3 ,and not get fractions.
No = 30.
3/5 * 30 =18
5/3 * 30 = 50
Error means = (difference/correct value ) * 100
Error = 32/50*100
Ans = 64.
No = 30.
3/5 * 30 =18
5/3 * 30 = 50
Error means = (difference/correct value ) * 100
Error = 32/50*100
Ans = 64.
(22)
M.Lokesh said:
3 years ago
Error comes from true value so;.
Error% = error/true value.
Error% = error/true value.
(18)
Tufayel BD said:
3 years ago
Let number is 100.
Actual Multiplication = (100 *5)/3 = 500/3.
Student multiplied = (100 *3)/5 = 300/5.
Error,
= (500/3) - (300/5),
= (2500 - 900)/15,
= 1600/15.
%Error = (1600 *100 *3)/(15*500) = 64%.
Actual Multiplication = (100 *5)/3 = 500/3.
Student multiplied = (100 *3)/5 = 300/5.
Error,
= (500/3) - (300/5),
= (2500 - 900)/15,
= 1600/15.
%Error = (1600 *100 *3)/(15*500) = 64%.
(17)
Helal said:
4 years ago
Let, X be the exact value.
And Y be the error value.
Now, the formula for percentage error= (X-Y)/X *100%
{(5/3-3/5)÷5/3}*100%.
= (16/15*3/5)*100%,
= 64%.
And Y be the error value.
Now, the formula for percentage error= (X-Y)/X *100%
{(5/3-3/5)÷5/3}*100%.
= (16/15*3/5)*100%,
= 64%.
(11)
Manoj Patil said:
4 years ago
In this question, take LCM of denominators of fractions 3/5 & 5/3 ( to make the calculation easier).
As the denominators are 5 & 3,
LCM is 15.
Now
Mistaken value = 15 * (3/5) = 9,
True value = 15 * (5/3)= 25.
Error = ( True value - mistaken value )/( true value),
= (25 - 9)/ 25 = 16/25,
Error %= Error * 100.
= (16/25)* 100.
= 64%.
Hope this helps.
As the denominators are 5 & 3,
LCM is 15.
Now
Mistaken value = 15 * (3/5) = 9,
True value = 15 * (5/3)= 25.
Error = ( True value - mistaken value )/( true value),
= (25 - 9)/ 25 = 16/25,
Error %= Error * 100.
= (16/25)* 100.
= 64%.
Hope this helps.
(9)
Raj said:
3 years ago
How 16/15 came? Please explain.
(9)
Ashi said:
2 months ago
Take LCM of the denominator i.e 3 x 5 = 15.
3/5*15 = 9 (this is the number we mistakely multiplied)
(but the number should have been this all along ) 5/3 * 15 = 25.
Difference -> 25 - 9 = 16.
Now, 16/25(the right number)* 100 = 64%.
3/5*15 = 9 (this is the number we mistakely multiplied)
(but the number should have been this all along ) 5/3 * 15 = 25.
Difference -> 25 - 9 = 16.
Now, 16/25(the right number)* 100 = 64%.
(8)
Guru said:
4 years ago
Lets take the number is 15.
Correct value is 5/3*15 = 25.
The error value is 3/5 * 15 = 9,
The difference is 11,
So 11/25*10 = 64.
Correct value is 5/3*15 = 25.
The error value is 3/5 * 15 = 9,
The difference is 11,
So 11/25*10 = 64.
(6)
Jatin Kumar said:
2 months ago
Let assume the number of 60.
now 3/5 * 60 = 36,
5/3 * 60 = 100.
Then the number is multiplied in to 100%.
36/100*100 = 36,
100-36 = 64.
now 3/5 * 60 = 36,
5/3 * 60 = 100.
Then the number is multiplied in to 100%.
36/100*100 = 36,
100-36 = 64.
(6)
Gokul Ramakrishnan said:
4 years ago
Hey take suppose a number 10 and multiply with 3/5 i.e >3/5*10=6, and the same number 10 is multiplied by 5/3.
i.e >5/3*10=16. 6=~17 then get the difference from each 17-6=11 then to find the real value and fake value.
Real value =17 anf the fake value =6.
So, we have the task to find the difference values percentage over the real value i.e >17 is 100% then 11 (difference value) is what percentage of 17 =64%.
i.e >5/3*10=16. 6=~17 then get the difference from each 17-6=11 then to find the real value and fake value.
Real value =17 anf the fake value =6.
So, we have the task to find the difference values percentage over the real value i.e >17 is 100% then 11 (difference value) is what percentage of 17 =64%.
(3)
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