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:
3
5
3
10
4
5
4
3
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 6 of 6.

Sree said:   1 decade ago
What is meant by reciprocal?

Jyothi said:   6 years ago
Thank You @Akash.

Saurin said:   8 years ago
Thank you all.


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