Multi-Step Equations Unit Test
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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
$2.50
In the problem, it is given that the 1-inch diameter marbles cost 30 cents less than the 2-inch marbles. Let's assume the cost of a 2-inch marble is x cents.
Since Rochelle bought 25 1-inch marbles for her project and spent exactly $10, we can set up the equation:
25(x - 30) = 1000
Multiplying 25 by (x - 30) and setting it equal to 1000, we get:
25x - 750 = 1000
Adding 750 to both sides of the equation, we get:
25x = 1750
Dividing both sides by 25 to solve for x, we get:
x = 70
Therefore, the cost of a 2-inch marble is $0.70. The correct answer is $0.70.