He probably means Geometric Distribution which is related to Geometric Series.You titled this "I am stuck on a geomtric series question" but there is no geometric series here.
I realise that now, which is why i was stuck. its a neg binomial distribution. I got the formula for it, so its dead easy. its r(1-p)/p^2 for the Var and r/p for the mean. I got the answer.He probably means Geometric Distribution which is related to Geometric Series.