Get the answers you've been looking for with the help of IDNLearn.com's expert community. Join our community to receive prompt, thorough responses from knowledgeable experts.

7. Three different coins are tossed together. Find the probability of getting:

a) Exactly 2 heads
b) At least 2 heads
c) At most 2 tails


Sagot :

Absolutely! Let's tackle this problem step by step.

### Total Possible Outcomes:
When tossing three coins, each coin has two possible outcomes: Heads (H) or Tails (T).
Thus, the total number of possible outcomes when three coins are tossed is:

[tex]\[ 2^3 = 8 \][/tex]

These possible outcomes are:
HHH, HHT, HTH, HTT, THH, THT, TTH, TTT

### a) Probability of getting exactly 2 heads:

First, we need to list out the outcomes where exactly two heads appear:
- HHT
- HTH
- THH

There are 3 outcomes with exactly 2 heads.

The probability of getting exactly 2 heads is the number of favorable outcomes divided by the total number of possible outcomes:

[tex]\[ P(\text{exactly 2 heads}) = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} = \frac{3}{8} \][/tex]

So, the probability is:

[tex]\[ P(\text{exactly 2 heads}) = 0.375 \][/tex]

### b) Probability of getting at least 2 heads:

Next, we list out the outcomes where there are at least 2 heads. This includes all cases of exactly 2 heads and the case where there are 3 heads:
- HHT (2 heads)
- HTH (2 heads)
- THH (2 heads)
- HHH (3 heads)

There are 4 outcomes with at least 2 heads.

The probability of getting at least 2 heads is:

[tex]\[ P(\text{at least 2 heads}) = \frac{4}{8} \][/tex]

So, the probability is:

[tex]\[ P(\text{at least 2 heads}) = 0.5 \][/tex]

### c) Probability of getting at most 2 tails:

Finally, we count the outcomes where there are at most 2 tails. This includes all cases where there are 0, 1, or 2 tails:
- HHH (0 tails)
- HHT (1 tail)
- HTH (1 tail)
- THH (1 tail)
- HTT (2 tails)
- THT (2 tails)
- TTH (2 tails)

There are 7 outcomes with at most 2 tails.

The probability of getting at most 2 tails is:

[tex]\[ P(\text{at most 2 tails}) = \frac{7}{8} \][/tex]

So, the probability is:

[tex]\[ P(\text{at most 2 tails}) = 0.875 \][/tex]

### Summary of Results:

a) Probability of getting exactly 2 heads: [tex]\( \boxed{0.375} \)[/tex]

b) Probability of getting at least 2 heads: [tex]\( \boxed{0.5} \)[/tex]

c) Probability of getting at most 2 tails: [tex]\( \boxed{0.875} \)[/tex]
We are delighted to have you as part of our community. Keep asking, answering, and sharing your insights. Together, we can create a valuable knowledge resource. For clear and precise answers, choose IDNLearn.com. Thanks for stopping by, and come back soon for more valuable insights.