Posted by **Ichigo** on Saturday, April 20, 2013 at 7:11am.

9 fair coins are independently tossed in a row. Let X be the random variable denoting the number of instances in which a Head is immediately followed by a Tail during these 9 tosses. The variance of X has the form ab, where a and b are coprime integers. What is the value of a+b?

Details and assumptions

Note: If we have 5 coins which are tossed as (HT)T(HT), there are 2 instances in which a Head is immediately followed by a Tail; they have been grouped.

## Answer this Question

## Related Questions

- Math - 9 fair coins are independently tossed in a row. Let X be the random ...
- math - 9 fair coins are independently tossed in a row. Let X be the random ...
- Math-Probability - Consider a collection of n biased coins, each showing Heads ...
- Math-Probability - Consider a collection of n biased coins, each showing Heads ...
- Math-Probability - Consider a collection of biased coins, each showing Heads ...
- probability - Tossing a pair of coins We have a white coin, for which P(Heads)=0...
- math - 25 independent, fair coins are tossed in a row. What is the expected ...
- statistics - Five coins all balanced the same were tossed 150 times. Note that, ...
- Combinations Maths - 25 independent, fair coins are tossed in a row. What is the...
- Probability - A fair coin is tossed repeatedly and independently. We want to ...

More Related Questions