Question

Question

Marbles come in two sizes: 1-inch diameter and 2-inch diameter. The 1-inch diameter marbles cost 30 cents less than the 2-inch marbles. Rochelle buys 25 1-inch marbles for her science project and spends exactly $10. Find the cost of a 2-inch marble.(1 point)
Responses

$2.80
$2.80

$0.70
$0.70

$0.10
$0.10

$2.50

Answer 1

Let the cost of a 2-inch marble be \( x \) dollars. Then the cost of a 1-inch marble will be \( x - 0.30 \) dollars.

Rochelle buys 25 1-inch marbles for $10, so we can set up the following equation:

\[ 25(x - 0.30) = 10 \]

Now, simplify this equation:

\[ 25x - 7.5 = 10 \]

Next, add 7.5 to both sides:

\[ 25x = 17.5 \]

Now, divide both sides by 25 to solve for \( x \):

\[ x = \frac{17.5}{25} = 0.70 \]

Thus, the cost of a 2-inch marble is $0.70.

So, the correct response is \( \text{$0.70} \).