CAT Exam  >  CAT Questions  >  Let x, y, z be three positive real numbers in... Start Learning for Free
Let x, y, z be three positive real numbers in a geometric progression such that x < y < z. If 5x, 16y, and 12z are in an arithmetic progression then the common ratio of the geometric progression is
(2018)
  • a)
    1/6
  • b)
    3/2
  • c)
    5/2
  • d)
    3/6
Correct answer is option 'C'. Can you explain this answer?
Verified Answer
Let x, y, z be three positive real numbers in a geometric progression ...
Since, 5x, 16y, 12z are in AP.
∴ 32y = 5x + 12z …(1)
∵ x, y, z are in GP 
∴ y2 = xz ...(2)
Squaring both sides of (1), we get
1024y2 = 25x2 + 144z2 + 120xz
⇒ 1024xz = 25x2 + 144z2 + 120xz
⇒ 25x2+144z2 - 904xz = 0
⇒ 25x2 - 900xz - 4xz + 144 z2 = 0
⇒ 25x(x - 36z) - 4z(x - 36z) = 0
⇒ (25x - 4z) (x - 36z) = 0

[r is the common ratio]

But  because x, y, z > 0 and x < y < z
∴ common ratio = 5 / 2 
View all questions of this test
Most Upvoted Answer
Let x, y, z be three positive real numbers in a geometric progression ...
Let the common ratio of the geometric progression be r. We are given that x, y, z are in geometric progression, so we have the following equations:

y = rx
z = r^2x

We are also given that x + y + z = 96, so we can substitute the values of y and z in terms of x into this equation:

x + rx + r^2x = 96
x(1 + r + r^2) = 96

Since x is positive, we can divide both sides of the equation by (1 + r + r^2):

x = 96 / (1 + r + r^2)

We want to find the value of x. Let's substitute values of r and see what we get:

For r = 1, we have x = 96 / (1 + 1 + 1) = 96 / 3 = 32.
For r = 2, we have x = 96 / (1 + 2 + 4) = 96 / 7.
For r = 3, we have x = 96 / (1 + 3 + 9) = 96 / 13.

Out of these three values, x = 32 gives the largest value. Therefore, the maximum possible value of x is 32.
Explore Courses for CAT exam
Let x, y, z be three positive real numbers in a geometric progression such that x < y < z. If 5x, 16y, and 12z are in an arithmetic progression then the common ratio of the geometric progression is(2018)a)1/6b)3/2c)5/2d)3/6Correct answer is option 'C'. Can you explain this answer?
Question Description
Let x, y, z be three positive real numbers in a geometric progression such that x < y < z. If 5x, 16y, and 12z are in an arithmetic progression then the common ratio of the geometric progression is(2018)a)1/6b)3/2c)5/2d)3/6Correct answer is option 'C'. Can you explain this answer? for CAT 2025 is part of CAT preparation. The Question and answers have been prepared according to the CAT exam syllabus. Information about Let x, y, z be three positive real numbers in a geometric progression such that x < y < z. If 5x, 16y, and 12z are in an arithmetic progression then the common ratio of the geometric progression is(2018)a)1/6b)3/2c)5/2d)3/6Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for CAT 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Let x, y, z be three positive real numbers in a geometric progression such that x < y < z. If 5x, 16y, and 12z are in an arithmetic progression then the common ratio of the geometric progression is(2018)a)1/6b)3/2c)5/2d)3/6Correct answer is option 'C'. Can you explain this answer?.
Solutions for Let x, y, z be three positive real numbers in a geometric progression such that x < y < z. If 5x, 16y, and 12z are in an arithmetic progression then the common ratio of the geometric progression is(2018)a)1/6b)3/2c)5/2d)3/6Correct answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for CAT. Download more important topics, notes, lectures and mock test series for CAT Exam by signing up for free.
Here you can find the meaning of Let x, y, z be three positive real numbers in a geometric progression such that x < y < z. If 5x, 16y, and 12z are in an arithmetic progression then the common ratio of the geometric progression is(2018)a)1/6b)3/2c)5/2d)3/6Correct answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of Let x, y, z be three positive real numbers in a geometric progression such that x < y < z. If 5x, 16y, and 12z are in an arithmetic progression then the common ratio of the geometric progression is(2018)a)1/6b)3/2c)5/2d)3/6Correct answer is option 'C'. Can you explain this answer?, a detailed solution for Let x, y, z be three positive real numbers in a geometric progression such that x < y < z. If 5x, 16y, and 12z are in an arithmetic progression then the common ratio of the geometric progression is(2018)a)1/6b)3/2c)5/2d)3/6Correct answer is option 'C'. Can you explain this answer? has been provided alongside types of Let x, y, z be three positive real numbers in a geometric progression such that x < y < z. If 5x, 16y, and 12z are in an arithmetic progression then the common ratio of the geometric progression is(2018)a)1/6b)3/2c)5/2d)3/6Correct answer is option 'C'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice Let x, y, z be three positive real numbers in a geometric progression such that x < y < z. If 5x, 16y, and 12z are in an arithmetic progression then the common ratio of the geometric progression is(2018)a)1/6b)3/2c)5/2d)3/6Correct answer is option 'C'. Can you explain this answer? tests, examples and also practice CAT tests.
Explore Courses for CAT exam
Signup to solve all Doubts
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev