binomial distribution (as level) help thank you!

[tanmaydube]

(6) Charlie finds that when she takes a cutting from a particular plant, the probability that it roots successfully is 1/3.
Find the number of cuttings that she should take in order to be 99% certain that at least one cutting root successfully.(Ans=12).

THANK YOU!

 

[1357913579]

soory for bad handwrting if you dont understand anything tell me

 

[prettydevil]

plz i dont get this at all