Practice questions

Aptitude practice questions (Group 4)

Questions 19 to 20 of 20

By TNPSC Guide editorial team · Last updated: 27.10.2026

1. Question 19

   Consider the following statements on the multiplicative factor method. 1. The ratio of each column is written as first-row value : second-row value. 2. For a quantity in direct proportion with the unknown, the inverse of that ratio is the multiplying factor. 3. For a quantity in inverse proportion with the unknown, the inverse of the ratio is also the multiplying factor. Which of these are correct?

   1. A. 1 only
   2. B. 2 and 3 only
   3. C. 1 and 2 only
   4. D. 1, 2 and 3
   Answer and explanation

   Correct answer: C. 1 and 2 only

   Ratio = first row : second row; for direct proportion take its inverse (20 days → 12 days: factor 12/20), for inverse proportion keep it (15 women → 32 women: factor 15/32); so 1 and 2 are correct and 3 is wrong.

   Source: கணக்கு, எட்டாம் வகுப்பு, தமிழ் வழி (Mathematics, Standard VIII, Tamil medium; Samacheer Kalvi) (இயல் 4 வாழ்வியல் கணிதம் (4.5 கலப்பு மாறல்), p. 148 (PDF p. 154))

2. Question 20

   Which of these pairs is in inverse variation?

   1. A. Workers and the time to finish the work
   2. B. Distance and time at a constant speed
   3. C. Things bought and the money spent
   4. D. Working hours and earnings
   Answer and explanation

   Correct answer: A. Workers and the time to finish the work

   Two quantities are in inverse variation when their product is constant (xy = k): for the same work, workers × time stays the same, so more workers need less time; distance and time at a constant speed, purchase and spending, and working hours and earnings vary directly (y/x = k).

   Source: கணக்கு, எட்டாம் வகுப்பு, தமிழ் வழி (Mathematics, Standard VIII, Tamil medium; Samacheer Kalvi) (இயல் 4 வாழ்வியல் கணிதம் (4.5 கலப்பு மாறல்), p. 147 (PDF p. 153))