When trying to find the probability of drawing a violet marble from a jar containing 9 red, 4 brown, 10 yellow, and 8 violet marbles
Number of marbles = 9 + 4 + 10 + 8 = sum
Number of violet marbles = 8
If you just pull one marble out at random then the probability that it is violet is
8 / sum
There are 13 blue marbles. The blue marbles are three more than twice the number of red marbles. How many red marbles are there? What are the correct answer
31
Let's use "r" to represent the number of red marbles.
We are given that there are 13 blue marbles.
We are also told that the number of blue marbles is three more than twice the number of red marbles:
Number of blue marbles = 3 + 2r
We can set up an equation to represent the total number of marbles:
Total number of marbles = number of red marbles + number of blue marbles
Total number of marbles = r + (3 + 2r)
Simplifying:
Total number of marbles = 3r + 3
We know that the total number of marbles is 13 + the number of red marbles:
Total number of marbles = 13 + r
So we can set these two equations equal to each other:
3r + 3 = 13 + r
Simplifying:
2r = 10
r = 5
Therefore, there are 5 red marbles.
To find the probability of drawing a violet marble from the jar, we need to determine the total number of marbles and the number of violet marbles in the jar.
In this case, we know that the jar contains:
- 9 red marbles
- 4 brown marbles
- 10 yellow marbles
- 8 violet marbles
To find the total number of marbles, we can add up the individual quantities:
9 + 4 + 10 + 8 = 31
The total number of marbles in the jar is 31.
Next, we need to determine the number of violet marbles. In this case, we know that there are 8 violet marbles in the jar.
Now that we have the total number of marbles (31) and the number of violet marbles (8), we can calculate the probability of drawing a violet marble.
Probability is calculated by dividing the desired outcome (8 violet marbles) by the total number of possible outcomes (31 marbles in total).
So, the probability of drawing a violet marble is:
8/31
Therefore, the answer is 8/31.