Sequence And Series Question 168

Question: The product of $ n $ positive numbers is unity. Their sum is

[MP PET 2000]

Options:

A) A positive integer

B) Equal to $ n+\frac{1}{n} $

C) Divisible by $ n $

D) Never less than

Show Answer

Answer:

Correct Answer: D

Solution:

Given $ x_1.x_2.x_3……….x_{n}=1 $ $ \because $ $ A\text{.M}\text{.},\ge G\text{.M}\text{.} $ \ $ ( \frac{x_1+x_2+x_3+……+x_{n}}{n} ),\ge ,{{(x_1.x_2.x_3…….x_{n})}^{\frac{1}{n}}} $ $ ={{(1)}^{\frac{1}{n}}}=1 $ \ $ x_1+x_2+x_3+……..+x_{n}\ge n $ \ $ x_1+x_2+x_3+…….+x_{n} $ can never be less than n.