Question

If mean of 1,2,3.....N is 6n/11 then find the value of n

Answer 1

Answer: There are 11 terms in this series.

Explanation:

Since we have given that the series i.e.

1,2,3.......n

So, we know that the sum of n terms is

$\frac{n(n+1)}{2}$

And the mean of n terms is given by

$\frac{n(n+1)}{2n}$

According to question,

$\frac{n(n+1)}{2n}=\frac{6n}{11}\\\\\frac{n+1}{2}=\frac{6n}{11}\\\\11(n+1)=12n\\\\11n+11=12n\\\\11=12n-11n\\\\11=n$

So, there are 11 terms in this series.

Answer 2

Answer:

n =11because

Step-by-step explanation:

n(n+1)/2n=6n/11

11(n+1)=12n

11n+11=12n

12n-11n=11

n=11