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 4 of 14.
Lorance Mathew said:
1 decade ago
There is a rule.
(Numerator of 1st Fraction X Denominator of 2nd Fraction - Numerator of 2nd Fraction X Denominator of 1st Fraction)/(Denominator of 1st Fraction X Denominator of 2nd Fraction).
= (5 X 5 - 3 X 3)/(5 X 3) = (25 - 9)/15 .
= 16/15.
(Numerator of 1st Fraction X Denominator of 2nd Fraction - Numerator of 2nd Fraction X Denominator of 1st Fraction)/(Denominator of 1st Fraction X Denominator of 2nd Fraction).
= (5 X 5 - 3 X 3)/(5 X 3) = (25 - 9)/15 .
= 16/15.
Sunil said:
1 decade ago
Why we finally multiplying with 3/5x?
Kondareddy said:
1 decade ago
So simple friends,
First find error.
error = correct value- wrong value;
error % is = (error/correct value)*100;
First find error.
error = correct value- wrong value;
error % is = (error/correct value)*100;
Sid toons said:
1 decade ago
Let the number be 300. Then 300* (3/5) = 180. And 300* (5/3) =500.
500-180 = 320 Now for checking percentage error,
320/500 * 100 = 64%.
500-180 = 320 Now for checking percentage error,
320/500 * 100 = 64%.
Shiv kumar said:
1 decade ago
Let no. be 100.
100*(3/5) = 60.
100*(5/3) = 166.65.
Error = (true value - false value)/true value.
Error% = error*100.
100*(3/5) = 60.
100*(5/3) = 166.65.
Error = (true value - false value)/true value.
Error% = error*100.
PRIYANKA said:
1 decade ago
True = 5/3.
False = 3/5.
Then false/true*100 = 3/5/5/3*100 = 36% WHICH IS CORRECT %.
TO FIND ERROR PERCENTAGE 100-36 = 64%.
False = 3/5.
Then false/true*100 = 3/5/5/3*100 = 36% WHICH IS CORRECT %.
TO FIND ERROR PERCENTAGE 100-36 = 64%.
SUNIL said:
1 decade ago
LET Number = 1.
Correct number = 5/3.
Incorrect number = 3/5.
We know that:
%error = (true value- false value)100/(true value).
%error = (5/3-3/5)100/(5/3).
Solve it and you got 64%.
Tips: When ever you got this type of question always choose 1 as no. It make your calculation easier and simplest.
Thanks.
Correct number = 5/3.
Incorrect number = 3/5.
We know that:
%error = (true value- false value)100/(true value).
%error = (5/3-3/5)100/(5/3).
Solve it and you got 64%.
Tips: When ever you got this type of question always choose 1 as no. It make your calculation easier and simplest.
Thanks.
Manikandan Kuppusamy said:
1 decade ago
Hi, I have one clarification.
Ques: A student multiplied a number by 3 instead of 6. What is the percentage error in the calculation?
As per above step,
We got 6x-3x = 3x, then.
3x*3x*100 = 900%. Is this correct? Please clarify me.
Ques: A student multiplied a number by 3 instead of 6. What is the percentage error in the calculation?
As per above step,
We got 6x-3x = 3x, then.
3x*3x*100 = 900%. Is this correct? Please clarify me.
Gokul prasanth said:
1 decade ago
Final step is (3x/3x)*100 = 50%.
Srinivas Dama said:
1 decade ago
If the number is x then,
=>x*3/5-x-5/3 = 16/15.
I got 16/15 is the difference of that numbers then how I can go to next step to get the answer can any explain clearly.
=>x*3/5-x-5/3 = 16/15.
I got 16/15 is the difference of that numbers then how I can go to next step to get the answer can any explain clearly.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers