When tossing 2 coins, we first need to determine the sample space. The sample space is the set of all possible outcomes. For 2 coins, each coin has 2 possible outcomes: heads (H) or tails (T).
The outcomes when tossing 2 coins can be listed as:
- HH (both heads)
- HT (first head, second tail)
- TH (first tail, second head)
- TT (both tails)
So, the sample space S is: {HH, HT, TH, TT}.
Now, let’s find the probability of getting exactly 1 head. In our sample space, we observe the following outcomes that result in exactly 1 head:
- HT
- TH
There are 2 favorable outcomes (HT and TH) out of a total of 4 possible outcomes (HH, HT, TH, TT).
The probability P of getting exactly 1 head is calculated as:
P(exactly 1 head) = Number of favorable outcomes / Total number of outcomes
Thus:
P(exactly 1 head) = 2 / 4 = 1/2
So, the probability of getting exactly 1 head when tossing 2 coins is 1/2.