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
$0.10
$0.10
$2.50
$2.50
$0.70
Let the cost of a 2-inch marble be x cents per marble.
According to the given information, the cost of a 1-inch marble is (x - 30) cents per marble.
Rochelle buys 25 1-inch marbles, so she spends (25 * (x - 30)) cents on 1-inch marbles.
This spent amount is equal to $10, so we can write the equation:
25 * (x - 30) = 1000
Divide both sides by 25:
x - 30 = 40
Add 30 to both sides:
x = 70
Therefore, the cost of a 2-inch marble is $0.70 each.