00:01
For these questions here, we're going to be doing a lot of work with the idea of classical probability, which basically tells us that the probability of an event occurring is equal to the number of ways the event can occur, divided by the total number of possible outcomes.
00:16
So for part a, probability of getting a red ball is going to be equal to the number of red balls, there are four red balls, divided by the total number of balls in the bag.
00:28
You can see that there are six black, four red, so there are ten total, which means that the probability is 0 .4.
00:34
For part b, let's see here, we have that total number of coins.
00:41
We have 10 worth one i don't know what currency that uses or that's supposed to be so i'll just say one r or rs.
00:52
We have 10 coins of one rs, 20 coins of two rs, we have five coins of five rs.
01:00
So we can see that we have a total of 35 coins and we want to find the probability of getting a coin of 5rs if one coin is chosen at random.
01:12
So we can see as mentioned there are five coins worth 5rs out of the 35 coins in the bag.
01:20
5 over 35 is going to be equal to 1 over 7.
01:28
And one second here let let me just make sure.
01:33
5 over 35, yeah, 1 over 7...