Hello there. To solve this question, we have to remember some properties about probabilities.
Given the following spinner:
We want to determine the probability of spinning a number less than 5.
For this, think of the numbers in the spinner as the following set:
We have 10 numbers and this is the size of the sample we're working with.
Now, we need to find the probability of spinning a number less than 5.
We can do this directly or using the complimentary event:
In this case, the probability of spinning a number that is greater than or equal to 5 is the complimentary probability of the one we want to determine and it is easier:
Notice we only have 3 numbers that are greater than or equal to 5: 5, 5 and 6.
Therefore, the probability is calculated as the ratio between the number of favorable events to an event E happening (3) and the size of the sample, 10.
In this case, we get
Adding the fractions, we get
Which is written in percent as