posted by Angela on .
In a game, a player tosses a coin 4 times. If the player gets 3 or 4 heads, he/she wins. What is the theoretical probability of winning this game?
I just need to know the outcomes. I don't know how to get them.
Please and Thank you.
Coin 1: 50% Heads
Coin 2: 50% Heads
Coin 3: 50% Heads
Coin 4: Irrelevent, because only 3 are needed.
50% x 50% x 50% = 12.5%
When you want to know the probability of all events occurring, multiply the probability of the individual events.
When you want to know the probability of either one event or another occurring, add the individual probabilities.
Probability of 3 heads is 1/2*1/2*1/2. Since the probability of the remaining toss can be either heads or tails, its proability is 1/2+1/2=1, so this has no effect on the multiplication. Probability of 3 heads = 1/8
Probability of 4 heads is 1/2*1/2*1/2*1/2 = 1/16.
The probability of getting either 3 heads or 4 heads is found by adding the two probabilities.
1/8 + 1/16 = 2/16 + 1/16 = 3/16 = 18.75%
I hope this helps a little more. Thanks for asking.