A fair coin is tossed 7 times. What is the probability that at least two heads appear? Solution the total number of outcomes if a coin is tossed 7 times is 14, At most 4 heads appear in the sense it may be 1,2,3 and 4. probability of getting one,two,three,four heads is 1/14,2/14,3/14,4/14 respectively.the probability of at most 4 heads is 1/14+2/14+3/14+4/14=10/14=5/7.