Aptitude - Numbers - Discussion
Discussion Forum : Numbers - General Questions (Q.No. 26)
26.
The difference between a positive proper fraction and its reciprocal is 9/20. The fraction is:
Answer: Option
Explanation:
| Let the required fraction be x. Then | 1 | - x = | 9 |
| x | 20 |
 |
1 - x2 | = | 9 |
| x | 20 |
20 - 20x2 = 9x
20x2 + 9x - 20 = 0
20x2 + 25x - 16x - 20 = 0
5x(4x + 5) - 4(4x + 5) = 0
(4x + 5)(5x - 4) = 0
| x = | 4 |
| 5 |
Discussion:
53 comments Page 4 of 6.
Vijay said:
8 years ago
They told in question the difference between +ve proper fraction and its reciprocal is 9/20. Means -> Positive proper fraction=1/x and its reciprocal is 1/1/x=x. Their difference is (1/x) -x=9/20. So we have to find x. Find x by the above method.
Pooja said:
8 years ago
@ Rima.
The numerator is less than the denominator.
Examples: 1/3, 3/4, 2/7. Improper Fractions: The numerator is greater than (or equal to) the denominator.
The numerator is less than the denominator.
Examples: 1/3, 3/4, 2/7. Improper Fractions: The numerator is greater than (or equal to) the denominator.
Shiva said:
8 years ago
Positive proper function is in form of 1/x and its reciprocal is x that why we are considering 1/x - x = 9/20.
Dharna said:
7 years ago
Answer should be 5/4 not 4/5.
Vicky said:
7 years ago
I think the right answer is 5/4.
Ref: RS Agarwal.
Ref: RS Agarwal.
(1)
Suresh said:
7 years ago
What is factorization? I am not understanding this.
Anomi said:
7 years ago
It must be x-1/x=9/20 in the first place.
Since +ve proper fraction x is always greater than it's reciprocal. For eg if we consider 3 as +ve proper fraction, then it's reciprocal is 1/3 which is obviously lesser than 3.
Since +ve proper fraction x is always greater than it's reciprocal. For eg if we consider 3 as +ve proper fraction, then it's reciprocal is 1/3 which is obviously lesser than 3.
Tobzs said:
6 years ago
4+5=9
4 * 5 = 20,
And 9/20 = 4/5 in the simplified form
So, 4/5 is the answer.
4 * 5 = 20,
And 9/20 = 4/5 in the simplified form
So, 4/5 is the answer.
Puja said:
6 years ago
Can anyone please explain how 25 and 9 came?
Sakshi sharma said:
6 years ago
Why have we taken the fraction as 1/x? what if we take it as a/b?
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