Question

Marbles come in two colors, blue and white. The blue marbles cost 50 cents more *
than the white marbles. Rocky buys 20 blue marbles and spends exactly $25. Find
the cost of the white marbles.

© 50cents

© 60cents

© 75cents

© 95cents

Answer 1

Let the cost of a white marble be \( w \) cents. Then, the cost of a blue marble would be \( w + 50 \) cents since it costs 50 cents more than a white marble.

According to the problem, Rocky buys 20 blue marbles for a total of $25. First, we need to convert $25 into cents:

\[
25 \text{ dollars} = 2500 \text{ cents}
\]

Now we set up the equation based on Rocky's purchase:

\[
20 \times (w + 50) = 2500
\]

Expanding this equation:

\[
20w + 1000 = 2500
\]

Next, we solve for \( w \) by subtracting 1000 from both sides:

\[
20w = 2500 - 1000
\]
\[
20w = 1500
\]

Now, divide by 20:

\[
w = \frac{1500}{20} = 75
\]

Thus, the cost of the white marbles is \( \boxed{75 \text{ cents}} \).