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:
138 comments Page 2 of 14.
Rohan said:
3 years ago
Just take lcm of 5 and 3 which will be 15.
Now,
3/5 * 15 = 9 and 5/3 * 15 = 25.
Now subtract 25 by 9 25 - 9 = 16.
Now 16/25 * 100 = 64%.
Now,
3/5 * 15 = 9 and 5/3 * 15 = 25.
Now subtract 25 by 9 25 - 9 = 16.
Now 16/25 * 100 = 64%.
(43)
Vinay said:
1 year 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.
(40)
Khushi said:
3 years ago
Step1: 5/3 * 100 = 166.66~167
Step2: 3/5 * 100 = 60
Step3: Difference of 167 and 60 i.e; 107
Step4: Error value = (error/true) * 100,
(107/166) * 100 = 64%.
Step2: 3/5 * 100 = 60
Step3: Difference of 167 and 60 i.e; 107
Step4: Error value = (error/true) * 100,
(107/166) * 100 = 64%.
(38)
Ashi said:
1 year 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%.
(30)
Saurabh Mishra said:
5 months ago
Suppose the number is 75.
Then 75*3/5 = 45.
And actual value is 75*5/3 = 125.
error = 125-45 = 80.
Now answer will be = (error value/actual value)*100.
(80/125)*100 = 64.
Then 75*3/5 = 45.
And actual value is 75*5/3 = 125.
error = 125-45 = 80.
Now answer will be = (error value/actual value)*100.
(80/125)*100 = 64.
(27)
M.Lokesh said:
4 years ago
Error comes from true value so;.
Error% = error/true value.
Error% = error/true value.
(18)
Tufayel BD said:
4 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:
5 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)
Jatin Kumar said:
1 year 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.
(11)
Vidhey said:
4 months ago
Incorrect:3/5. 15 * 3/5 = 9.
Correct: 5/3. 15 * 5/3 = 25.
LCM=15.
% = 16/25 * 100 = 64%.
Correct: 5/3. 15 * 5/3 = 25.
LCM=15.
% = 16/25 * 100 = 64%.
(11)
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