Repeating a message
A (very) noisy channel is known to flip bits 20% of the time. Alice decides to send the same bit multiple times, and Bob will interpret the message as the bit he receives more times (e.g. if Bob received 0, 1, 1, he would conclude the message was 1).
If Alice wants to ensure the message is correctly received with probability at least 95%, what is the minimum number of times Alice needs to send each bit?