Calculating the probability of an event is very simple if we know the number of favorable outcomes and the number of possible outcomes of the event.
- Number of favorable resultsThe number of times the event can occur. For example, on a six-sided die we have three favorable outcomes of getting an even number.
- Number of possible outcomesHere we write the number of possible outcomes that the event has. Continuing with the example of the die, we have a total of six possible outcomes.
Once we have the above data, we enter them in the probability calculatorIf we press the calculate button, we will automatically obtain the probability that this event may come true.
How to calculate the probability of an event
Calculating the probability of something happening is very simple. We simply have to apply the following division:
probability % = favorable events / total results x 100
In other words, the steps to follow are:
- Determine the number of favorable results we can get in an event. For example, if we want to roll an odd number on a six-sided die, the number of favorable events we can have is 3 (the numbers 1, 3 and 5).
- See the number of possible results for that event. Following the above example of the die, there will be a total of 6 possible events.
With the above data, we simply have to substitute in the formula that we have put a few lines above and solve the operation.
Examples of probability of occurrence
For example, do youwhat is the probability of winning the lottery?? In this case, we have a total of 100,000 results ranging from the number 00000 to 99,999 but only one of them will make us millionaires. Therefore:
probability = 1 / 100.000 x 100 = 0,001 %
We have one in 100,000 chance of winning the lottery.
What about chances of winning the euromillions? In this case, we have to match 5 numbers and 2 stars, which gives a single winning result among 116,531,800 possible combinations.
probability = 1 / 116,531,800 x 100 = 0.000000858134861%
The result is devastating because our chances of winning the euromillions prize are practically nonexistent. so the only thing left to do is to rely on luck.
To give a more everyday example, what is the probability that we get a 3 on a die? We know that it has 6 different numbers, so the chances of hitting our bet are reduced to:
1 / 6 x 100 = 16,66%