Probability drives me crazy
I couldn't figure out how it solves
could you help me please
Multiple Choice Exam
Each question on a 5 questions multiple choice examination has 4 choices,only one of which is correct . If a student answers each question on a random fashion, what's the probability that the student answers exactly 2 question incorrectly ?
My answer :
# I said if the student answers 2 question incorrectly is the same as if he answers ignore any 2 question
tell me how to solve it plz
BUT the right answer is ( )
Jelly Beans in a Bag
Abag contains 4 red and 6 green jelly beans.
a) if 2 jelly beans are randomly selected in succession with replacement, determine the probability that both are red.
b)if the selection is made without replacement .determine the probability that both are red.
BUT the right answer is
Tell me please how to solve them