Answer:
a. 1/16 which is 6.2500%
b. 15/16 which is 93.7500%
Step-by-step explanation:
a. For each 'coin toss' the probability of getting tails is 1/2. If you toss the coin 4 times, the probability of getting tails all times is 1/2 * 1/2 * 1/2 * 1/2 = 1/16.
b. This one is a bit trickier.
When flipping four coins, you either could get all four heads or you could get at least one tail. Both events cannot happen at the same time. This means the two events are complementary.
Complementary events occur when there are only two outcomes, for example passing an exam or passing an exam. The complement means the exact opposite of an event.
Complementary probabilities always add to 1.
We saw in part (a) that the probability you get all tails is 6.25% or 1/16.
0.0625 was the probability of getting all four heads, so 0.9375 is the probability of anything else (getting one or more tails).
The decimal 0.9375 converts to the fraction 15/16.
The probability is 93.75%.