iran-konkur 2016 Q144

iran-konkur · Other · konkur-riazi_1395_specialized Binomial Distribution Find Minimum n for a Probability Threshold
144. We toss a fair coin at least a few times so that we are more than 99\% certain that the result of three heads has occurred at least once. How many times at minimum must we toss?
(1) $12$ (2) $12$ (3) $18$ (4) $19$
\textbf{144.} We toss a fair coin at least a few times so that we are more than 99\% certain that the result of three heads has occurred at least once. How many times at minimum must we toss?

(1) $12$ \quad (2) $12$ \quad (3) $18$ \quad (4) $19$