All Exams Test series for 1 year @ ₹349 only
Question

If p, \(g_1\), \(g_2\) and q are in GP and m is the arithmetic mean of p and q, then \(\frac{g_1^2}{g_2} + \frac{g_2^2}{g_1}\) is equal to

This question was previously asked in
NDA 2 2026 GAT Question Paper (13-Sep-2026)
The correct answer is
2m

Geometric Progression (GP) and Arithmetic Mean (AM) Problem

The question asks for the value of the expression \(\frac{g_1^2}{g_2} + \frac{g_2^2}{g_1}\), given that p, \(g_1\), \(g_2\), and q are terms in a Geometric Progression (GP), and m is the Arithmetic Mean (AM) of p and q.

GP Properties Analysis

Let the first term of the GP be p and the common ratio be r.

  • Since p, \(g_1\), \(g_2\), q are in GP, we can express the terms as:
    • \(g_1 = p \cdot r\)
    • \(g_2 = p \cdot r^2\)
    • \(q = p \cdot r^3\)

Simplifying the Expression

Now, substitute these terms into the expression \(\frac{g_1^2}{g_2} + \frac{g_2^2}{g_1}\):

  • Calculate the first part: \( \frac{g_1^2}{g_2} = \frac{(p \cdot r)^2}{p \cdot r^2} = \frac{p^2 \cdot r^2}{p \cdot r^2} = p \)
  • Calculate the second part: \( \frac{g_2^2}{g_1} = \frac{(p \cdot r^2)^2}{p \cdot r} = \frac{p^2 \cdot r^4}{p \cdot r} = p \cdot r^3 \)
  • Recognize that \(p \cdot r^3\) is equal to the fourth term, q.
  • So, the expression simplifies to: \( \frac{g_1^2}{g_2} + \frac{g_2^2}{g_1} = p + q \)

Relating to Arithmetic Mean (AM)

The problem states that m is the Arithmetic Mean (AM) of p and q.

  • By definition of AM: \( m = \frac{p+q}{2} \)
  • Rearranging this formula gives: \( p+q = 2m \)

Final Calculation

Substitute the value of \(p+q\) back into the simplified expression:

  • \( \frac{g_1^2}{g_2} + \frac{g_2^2}{g_1} = p + q = 2m \)

Therefore, the value of the expression is \(2m\).

Was this answer helpful?

Similar Questions

  1. If g is the geometric mean of 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, then which one of the following is correct?

  2. What is the greatest value of the positive integer n satisfying the condition \(1 + \frac{1}{2} + \frac{1}{4} + \frac{1}{8} + \ldots + \frac{1}{{{2^{{\rm{n}} - 1}}}} < 2 - \frac{1}{{1000}}?\)

  3. A geometric progression (GP) consists of 200 terms. If the sum of odd terms of the GP is m, and the sum of even terms of the GP is n, then what is its common ratio?

  4. If the second term of a GP is 2 and the sum of its infinite terms is 8, then the GP is

  5. If m is the geometric mean of \({\left( {\frac{{\rm{y}}}{{\rm{z}}}} \right)^{\log \left( {{\rm{yz}}} \right)}},{\rm{\;}}{\left( {\frac{{\rm{z}}}{{\rm{x}}}} \right)^{\log \left( {{\rm{zx}}} \right)}}{\rm{\;and\;}}{\left( {\frac{{\rm{x}}}{{\rm{y}}}} \right)^{\log \left( {{\rm{xy}}} \right)}}\) then what is the value of m?

  6. The value of the infinite product \({6^{\frac{1}{2}}} \times {6^{\frac{1}{2}}} \times {6^{\frac{3}{8}}} \times {6^{\frac{1}{4}}} \times \ldots \) is

  7. The geometric mean of the observations x 1, x 2, x 3, … x nis G 1. The geometric mean of the observations y 1, y 2, y 3,… y nis G 2. The geometric mean of observations \(\frac{{{{\rm{x}}_1}}}{{{{\rm{y}}_1}}},\frac{{{{\rm{x}}_2}}}{{{{\rm{y}}_2}}},\frac{{{{\rm{x}}_3}}}{{{{\rm{y}}_3}}}, \ldots \frac{{{{\rm{x}}_{\rm{n}}}}}{{{{\rm{y}}_{\rm{n}}}}}\) is

  8. If p, q, r are in one geometric progression and a, b, c are in another geometric progression, then ap, bq, cr are in

  9. What is the sum of the series 0.5 + 0.55 + 0.555 + … to n terms?

  10. Let t1, t2, t3 ... be in GP. What is \(\rm \left(t_1 t_3 \ldots t_{21}\right)^{\frac{1}{11}}\) equal to ?


Important Questions from Geometric Progressions

  1. If g is the geometric mean of 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, then which one of the following is correct?

  2. What is the greatest value of the positive integer n satisfying the condition \(1 + \frac{1}{2} + \frac{1}{4} + \frac{1}{8} + \ldots + \frac{1}{{{2^{{\rm{n}} - 1}}}} < 2 - \frac{1}{{1000}}?\)

  3. The sum of even numbers from 1 to 40 is:

  4. The minimum value of the sum of real numbers a-5, a-4, 3a-3, 1, a8 and a10 with a > 0 is:

  5. The arithmetic mean, geometric mean and median of six positive numbers a, a, b, b, c, c where a < b < c are \(\frac 7 3,\) 2, 2 respectively. Then what is the sum of the squares of all the six numbers?

Need Expert Advice?
Test Series
NDA img
Defence
NDA 2026 Mock Test Series (Latest Pattern)
503 Tests 1 Tests Free
1066 Attempts
4.6(137)
English, Hindi

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App