If three inches of rope cost 7 cents, what is the cost per inch in cents?

• A. 7/3
• B. 7/2
• C. 7
• D. 3

Answer: (A)

This item is about finding a unit rate: cost per inch is the total cost divided by the total inches. With 7 cents for 3 inches, the cost per inch is 7 ÷ 3, which equals 7/3 cents. That makes sense because the price per inch drops when you spread the same total cost over more inches. The other options would reflect different scenarios: 7/2 would be if it were 7 cents for 2 inches; 7 would be the cost per inch if each inch cost 7 cents; 3 would be the cost per inch if each inch cost 3 cents. Since 7 cents buys 3 inches, the per-inch amount must be 7/3 cents.