If the survival times of 10 lives in a survivorship group are independent with survival defind in [table in our book], exhibit the p.f. of L(65) and the mean and variance of L(65).

I found the mean to be E[L(65)] = l0[65P0] = l65 = 7.7107 , which I know is correct but I'm not sure how to get the variance. Thanks!