## Problem of the Day #384: Coin FlippingApril 6, 2012

Posted by Saketh in : potd , trackback

Albert has $10$ different coins, weighted to have a $\frac{1}{3}$, $\frac{1}{5}$, $\frac{1}{7}$, $…$ $\frac{1}{21}$ chance of landing heads, respectively. If he flips all of them, what is the probability that he obtains an odd number of heads?