Machine-translated by Google. Questions are authored in English.
Top

Discussion

Match List I with List II.

List IList II
a. 3rd proportion to 16 and 32 isI. 21
b. 3rd proportion to 6 and 18 isII. 54
c. 4th proportion to 3, 7 and 9 isIII. 64
d. 4th proportion to 4, 16 and 7 isIV. 28

Choose the most appropriate answer from the options given below:

  • A.a-III, b-I, c-II, d-IV
  • B.a-I, b-IV, c-III, d-II
  • C.a-III, b-II, c-I, d-IV
  • D.a-II, b-III, c-IV, d-I

Answer: C

The correct matching is a-III, b-II, c-I, d-IV.

The third proportional to \(a\) and \(b\) is \(b^2/a\); the fourth proportional to \(a, b, c\) is \(bc/a\).

\[ \begin{aligned} \text{a: } 32^2/16 &= 64 \\ \text{b: } 18^2/6 &= 54 \\ \text{c: } 7 \times 9/3 &= 21 \\ \text{d: } 16 \times 7/4 &= 28 \end{aligned} \]

So a goes with 64 (III), b with 54 (II), c with 21 (I) and d with 28 (IV). Option A swaps b and c, giving 6 and 18 a third proportional of 21, which does not satisfy \(6 : 18 = 18 : x\).

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.