please help i dont understand and explain every number and how you got it. i will thumbs up if correct

A future project has an uncertain finish time and the finish time follows a normal distribution. The project's expected finish time is 21 weeks, and the project variance is 8 weeks. If the project deadline is set to be 59 weeks, then what is the probability that the project would need more than the given deadline to complete? Input should be either 1 or 2 , with 1 represents "more than 50% " and 2 represents "equal or less than 50%