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 8 of 14.
Vengamanaidu said:
9 years ago
Thank you @Michael, your explanation is the best method.
Vipin said:
9 years ago
It's simple,
1. Let number be x
2. Error = true value - false value
3. 5/3 x - 3/5 = 16/15 x
4. We know the formula -> change = difference / initial value * 100
So, 16/15 x / 5/3 x *100 = 64 % -----> percentage we right because in question we say that error %.
1. Let number be x
2. Error = true value - false value
3. 5/3 x - 3/5 = 16/15 x
4. We know the formula -> change = difference / initial value * 100
So, 16/15 x / 5/3 x *100 = 64 % -----> percentage we right because in question we say that error %.
Naveena said:
9 years ago
Here,
True value = 5/3.
False value = 3/5.
To find the error => error = true value - false value.
=5/3 - 3/5.
Error = 16/15.
To find error % => error%= (error/true value) * 100.
=16/15 / 5/3 *100.
Error% = 64%.
Since, this is the simplification of this problem.
True value = 5/3.
False value = 3/5.
To find the error => error = true value - false value.
=5/3 - 3/5.
Error = 16/15.
To find error % => error%= (error/true value) * 100.
=16/15 / 5/3 *100.
Error% = 64%.
Since, this is the simplification of this problem.
Gabriel said:
9 years ago
Two groups of students went into the shop. The first group bought four hot dogs and six juices and paid N$71.00 the second group bought three hotdogs and seven juices and paid N$67.00 what were the prices for these items (hotdog&juice)?
Can anyone solve this problem?
Can anyone solve this problem?
Triveni said:
9 years ago
@Chris It.
You clear my doubt. Thank you so much.
You clear my doubt. Thank you so much.
Satya said:
9 years ago
@Gabriel.
We need to write the statement in the form of equations:
The price of
4 hd + 6 ju =71--> (1)
3 hd + 7 ju =67--> (2)
Multiply 3 & 4 with eq.(1) and (2) respectively.(aim is to make equal Coeff. of hd) then new equation will be;
12 hd + 18 ju = 213--> (3)
12 hd + 28 ju = 268--> (4)
Subtract eq (3) from eq.(4)
Answer is
Juice = $5.5.
Hot dogs = $9.5.
We need to write the statement in the form of equations:
The price of
4 hd + 6 ju =71--> (1)
3 hd + 7 ju =67--> (2)
Multiply 3 & 4 with eq.(1) and (2) respectively.(aim is to make equal Coeff. of hd) then new equation will be;
12 hd + 18 ju = 213--> (3)
12 hd + 28 ju = 268--> (4)
Subtract eq (3) from eq.(4)
Answer is
Juice = $5.5.
Hot dogs = $9.5.
Jac said:
9 years ago
This session is very helpful. Thanks.
Ybm said:
9 years ago
The shortcut is (Diff ÷ original number)100.
Raj said:
9 years ago
What is the logic behind the term (16x/15 * 3/5x)?
MaDX said:
9 years ago
@Raj, We have to find error %.
And like S.P and C.P, the percentage are calculated from the original value.
1.First we have to find the error:
Error = Original value - Wrong value.
= (5/3 x) - (3/5 x).
= 16/15x.
2.Then percentage for error in original.
error% = error/original * 100;
= (16/15 x)/(5/3 x) * 100.
= 64%.
So 64%.
And like S.P and C.P, the percentage are calculated from the original value.
1.First we have to find the error:
Error = Original value - Wrong value.
= (5/3 x) - (3/5 x).
= 16/15x.
2.Then percentage for error in original.
error% = error/original * 100;
= (16/15 x)/(5/3 x) * 100.
= 64%.
So 64%.
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