What is the probability that you get at least one head in 4 tosses of a fair coin?
15/16, 3/4, 1/2, or 1/16?
It equals 1 minus the probability of zero heads. (If you get at least one, you don't get zero)
= 1 - (1/4)^4
which is one of your choices
15/16, 3/4, 1/2, or 1/16?
= 1 - (1/4)^4
which is one of your choices