If the variance of first n natural numbers is 2 and the variance of first m odd natural numbers is 40, then `m +n =`

Answer

16

Explanation

Variance of first natural numbers is ` (n ^(2) -1)/(12) = 2 implies n ^(2) = 25 implies n =5`
and variance of first odd natural numbers is
`2 ^(2) ((m ^(2) -1))/(12) = 40 implies (m ^(2) -1)/(12)=10`
`implies m ^(2) -1 =120 implies m^(2) =121 implies m =11`