[طالب مضيع]

A student takes a 7 question multiple choice quiz with 4 choices for each question if the student at random on each question what is the probability that the student gets exactly 3 questions correct ?
الاجابه :
P=p(correct(= 1/4
Q=p(not correct( = 1-p =3/4
X=3
p(x=3= 35 * 1/64 * 81/256
ابغا اعررف كيف جججات 35