february(15-29)2009- maths

A bag contains a coin of value M and a number of other coins whose aggregate value is m. A person draws one at a time till he draws the coin M. Find the value of his expectation. i like this problem , because its got a one line solution, yet gud thinking involved

my previous question was already posted by eureka. i did not notice that. so a new one.

Let X be a random variable such that P(X<=0) = 0 and let E(X) exist. Show that

P(X≥2E(X)) ≤ 0.5.

if u r able to do this , i think u need not worry about binomial distribution.