1.

The arthmetic mean of the numbers `1,3,3^(2), … ,3^(n-1),` isA. `(3^(n)-1)/(2)`B. `(3^(n)-1)/(2n)`C. `(3^(n)+1)/(2)`D. `(3^(n)+1)/(2n)`

Answer» Correct Answer - B
Let M be the required mean. Then,
`M=(1+3+3^(2)+ ... +3^(n-1))/(n)`
`rArr M=(1xx((3^(n)-1)/(3-1)))/(n)=(3^(n)-1)/(2n)`


Discussion

No Comment Found

Related InterviewSolutions