# math

posted by
**Angela**
.

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%

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.