Answer:
5/8
Step-by-step explanation:
Use binomial probability:
P = nCr pʳ qⁿ⁻ʳ
where n is the number of trials,
r is the number of successes,
p is the probability of success,
and q is the probability of failure (1−p).
The number of trials is n = 3.
The number of heads is r = 1.
The probability of heads is p = ½.
The probability of getting 1 heads and 2 tails is:
P = ₃C₁ (½)¹ (1 − ½)³⁻¹
P = 3 (½) (½)²
P = 3/8
So the probability of not getting 1 heads and 2 tails is:
1 − P = 5/8
