wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

If x1,x2,......,xn are n variables such that ni=1(2xi+5)=1600 and ni=1(x2i4)=900. If ni=1(xi+1)2=250 then the value of n is

A
15
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
20
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
10
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
5
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 10
Given: ni=1(2xi+5)=1600, ni=1(x2i4)=900 and ni=1(xi+1)2=250

Consider ni=1(2xi+5)=1600
2ni=1xi+5n=1600
( ni=1a=an, where a is any constant)
2ni=1xi=16005n..........(i)

Also ni=1(x2i4)=900
ni=1x2i4n=900
ni=1a=an, where a is any constant)
ni=1x2i=900+4n........(ii)

And, ni=1(xi+1)2=250
ni=1(x2i+2x1+1)=250n
ni=1x2i+2ni=1x1+n=250n
ni=1a=an, where a is any constant)
(900+4n)+(16005n)+n=250n [from (i) and (ii)]
2500=250n
n=10

Hence, the correct answer is option c.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Mean
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon