Zach said he would help Stuart clean his room if Stuart flips a coin 4 times and gets heads all 4 times. What is the probability that Stuart will flip a coin 4 times and get heads all 4 times?
The probability of getting heads on any one throw is 1/2. The probability of getting four heads in a row therefore is (1/2)x(1/2)x(1/2)x(1/2), OR (1/2)4 OR 1/16.