سؤال في الاحصاء

[كلي تميز]

السلام عليكم ورحمة الله وبركاته
يا حبايبي انا ما اعرف افرق بين قاعدة at lest /at most
وابغى حل هذا السؤال
28. In a certain company, it is known that 20% of the staff members are smokers. A random sample of 5 staff members is selected at random, let X represents the number of smoker in the sample.Find the probability that at most 4 staff members are smokers.
A) 0.00032
B) 0.0016
C) 0.8
D) 0.99968