1.

1,2,2,3,3,3,4,4,4,4,5,5,5,5,5,6,6,6,6,6,6, तथा 7,7,7,7,7,7,7 का समान्तर माध्य ज्ञात करे ?A. 4B. 5C. 14D. 20

Answer» Correct Answer - B
According to question
Avg. `=(1+2+2+3+3+3+4+4+4+4+5+5+5+5+5+6+6+6+6+6+6+7+7+7+7+7+7+7)/28`
Avg. `(1+2xx2+3xx3+4xx4+5xx5+6xx6+7xx7)/28`
Avg.=`(1+4+9+16+25+36+49)/28`
Avg. =5
Alternate :
we know that sum of `n^2` terms
`=(n(n+1)(2n+1))/6`
`=(7xx8xx15)/6=(7xx150)/6=140`
here terms are 28.
`therefore` Average =`140/28=5`


Discussion

No Comment Found

Related InterviewSolutions