Test Index

UPSC NDA 2 2016 Mathematics Solved Paper

Show Para Hide Para

Consider the following for the next three (03) items that follow:

Let a,x,y,z,b be in A.P,where

x+y+z=15

.Leta,p,q,r,b be in HP, where

p^{-1}+q^{-1}+r^{-1}=\frac{5}{3}

[NDA II 2016]

© examsnet.com

Question : 17 of 120

Marks: +1, -0

What is the value of xyz?

120
105
90
Cannot be determined

Solution:

On solving eq(l)& (2), we get

(i)

a=1

&

b=9\Rightarrow a+4d=9\Rightarrow d=2

(ii)

a=9

&

b=1\Rightarrow a+4d=1\Rightarrow d=-2

For

a=1

&

d=2

x=3,y=5

&

z=7

For

a=9

&

d=-2

x=7,y=5

&

z=3

\Rightarrow xyz=7\times 5\times 3=105

© examsnet.com

Go to Question:

Prev Question

Next Question