Bunuel wrote:
If a fair coin is tossed 4 times, what's the probability that at least 3 of the 4 tosses will come up heads?
A. 1/16
B. 1/4
C. 5/16
D. 7/16
E. 11/16
For 4 tosses P of getting exactly heads = (1/2)^4= 1/16
P of getting exactly 3 heads and 1 tail= 4c3* (1/2)^4= 1/4
1/16+1/4= 5/16 option C