Two geometric means a, b are inserted between x and y such that a3 + b3 = n (ab) A,
where A is the arithmetic mean of x and y. What is value of n?
Two geometric means a, b are inserted between x and y such that a3 + b3 = n (ab) A, where A is the arithmetic mean of x and y. What is value of n?
Option 1 -
1
Option 2 -
2
Option 3 -
3
Option 4 -
4
-
1 Answer
-
Correct Option - 2
Detailed Solution:x, a, b, y are in GP
a = xr
b = xr2
y = xr3
r =
rewrite,
a = x2/3.y1/3
b = x1/3.y2/3
a × b = x × y
a3 + b3 = x2y + y2 x
= xy (x+y)
= xy (2A) ……………
Hence, n = 2
Taking an Exam? Selecting a College?
Get authentic answers from experts, students and alumni that you won't find anywhere else
Sign Up on ShikshaOn Shiksha, get access to
- 65k Colleges
- 1.2k Exams
- 688k Reviews
- 1800k Answers