A box contains 5 red marbles, 8 white marbles and 4 green marbles. One marble is taken out of the box at random. What is the probability that the marble taken out will be red ?

Answer

To find the probability that a marble taken out of the box will be red, we can follow these steps:

### Step 1: Determine the total number of marbles.
We have:
- 5 red marbles
- 8 white marbles
- 4 green marbles

To find the total number of marbles, we add these together:
\[ \text{Total number of marbles} = 5 + 8 + 4 = 17 \]

### Step 2: Identify the number of favorable outcomes.
The favorable outcomes for our event (drawing a red marble) is the number of red marbles, which is:
\[ \text{Number of red marbles} = 5 \]

### Step 3: Calculate the probability.
The probability \( P \) of drawing a red marble is given by the formula:
\[ P(\text{Red}) = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} \]
Substituting the values we found:
\[ P(\text{Red}) = \frac{5}{17} \]

### Final Answer:
The probability that the marble taken out will be red is \( \frac{5}{17} \).

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