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.

Answer 1

To find the cost of a 2-inch marble, set up an equation using the given information and solve for 'x'. The cost of a 2-inch marble is 70 cents.

Step-by-step explanation:

To find the cost of a 2-inch marble, we need to set up an equation using the given information. Let's say the cost of a 2-inch marble is 'x' cents. We know that the 1-inch diameter marbles cost 30 cents less than the 2-inch marbles, so the cost of a 1-inch marble would be 'x - 30' cents.

Rochelle buys 25 1-inch marbles and spends exactly $10. We can set up the equation:

25(x - 30) = 1000 (since 1 dollar is equal to 100 cents).

Simplifying the equation, we get:
25x - 750 = 1000
25x = 1750
x = 70

Therefore, the cost of a 2-inch marble is 70 cents.