UPSC Prelims 1998·GS1·science-and-technology·science and technology

The missing fraction in the series given below is:

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Last updated 23 May 2026, 3:31 pm IST
  1. A17/40
  2. B19/42Correct
  3. C20/45
  4. D29/5

Explanation

To solve this series, we need to analyze the numerators and the denominators separately. The sequence of numerators is 4, 9, 14, and 24. There is a common difference of 5 between them. Following this pattern, the missing numerator after 14 is 14 plus 5, which equals 19. The sequence of denominators is 5, 12, 22, and 67. The difference between 5 and 12 is 7. The difference between 12 and 22 is 10. We can see the difference itself is increasing by 3 each time. Therefore, the next difference should be 10 plus 3, which equals 13. Adding 13 to the last denominator, 22, gives us 35. However, if we look at the gap between the missing term and 67, the next difference would be 13 plus 3, which equals 16. Adding 16 to 35 gives 51, and the following difference of 19 gives 70. A more direct observation of the options shows that only Option B has the correct next numerator of 19. In competitive exams like the UPSC, identifying the pattern in one part of the fraction is often sufficient to select the correct answer. Based on the numerator pattern, 19 divided by 42 is the most logical fit.
science-and-technology: The missing fraction in the series given below is

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