Let's break down the problem to find the correct equation.

Charles has 24 marbles in total, and he has 6 more yellow marbles than blue marbles. Let:

• $n$ be the number of blue marbles.
• The number of yellow marbles would then be $n + 6$, as there are 6 more yellow marbles than blue.

The total number of marbles is the sum of the blue and yellow marbles, which gives us the equation: $n + (n + 6) = 24$

Simplifying the equation: $2n + 6 = 24$ Subtracting 6 from both sides: $2n = 18$ Dividing by 2: $n = 9$

So, Charles has 9 blue marbles and $9 + 6 = 15$ yellow marbles.

The equation that represents this situation is: $n + (n + 6) = 24$ where $n$ is the number of blue marbles.

Thus, the correct answer is the first option: $n + (n + 6) = 24, \text{ where } n \text{ is the number of blue marbles.}$

Would you like more details or have any questions? Here are some related questions for practice:

1. What if Charles had 5 more yellow marbles instead of 6? What would the equation be?
2. How many yellow marbles does Charles have if he has 24 marbles and 8 more yellow marbles than blue?
3. What if Charles had 10 more blue marbles than yellow ones, and still 24 marbles in total? What would the equation look like?
4. What if Charles had 30 marbles in total, and 6 more yellow marbles than blue? How would that change the equation?
5. What would the equation be if Charles had 24 marbles, but now with twice as many yellow marbles as blue?

Tip: When translating word problems to equations, carefully define your variables and ensure they represent the quantities given in the problem.