Marbles come in two sizes: 2-inch diameter and 3-inch diameter. The 3-inch diameter marbles cost 50 cents more than the 2-ich marbles. Jorge buys 20 3-inch marbles for a science project and spends exactly $16. Find the cost of a 2-inch marble.

$0.50

$0.20

$0.40

$0.30

1 answer

Let's assume that the cost of a 2-inch marble is x cents.

Since the 3-inch marbles cost 50 cents more than the 2-inch marbles, the cost of a 3-inch marble is x + 50 cents.

Jorge buys 20 3-inch marbles for a total cost of $16.

Therefore, the equation that represents this situation is:
20(x + 50) = 1600

Simplifying the equation:
20x + 1000 = 1600

Subtracting 1000 from both sides of the equation:
20x = 600

Dividing both sides of the equation by 20:
x = 30

Therefore, the cost of a 2-inch marble is $0.30.