No worries, i finally got a hang of this problem. Thanks for all your help.
Well PF actually forbade you guys to solve the problem because it was in the wrong section,i'm new to the forum and am still getting used to it.
By the way about showing my work, what if i didn't really understand the...
A boy is playing with a biased coin. The probabilty of obtaining a head with the coin is 0.4. Determine the probability that the boy will require at least eleven tosses before obtaining his third head.
I have been trying but can't get it at all... Can someone please explain me how to solve...