Question

Qian used the rule "divide the length of a piece of wood by 3 to get the number of nails needed. "If 3 nails are needed for a piece of wood that is 9 inches and 13 nails are needed for a piece of wood that is 39 inches, what is the length of a piece of wood that requires 8 nails?
O 18 inches
O 21 inches
O 24 inches
O 27 inches

Answer 1

To solve this problem, we can set up a proportion to find the length of a piece of wood that requires 8 nails.

Let x be the length of the piece of wood.

According to the given information, we have the following proportion:

(9 inches) / 3 nails = (x inches) / 8 nails

Cross-multiplying, we get:

(9 inches) * 8 nails = (x inches) * 3 nails

72 inches = 3x

Dividing both sides by 3, we find:

24 inches = x

Therefore, the length of a piece of wood that requires 8 nails is 24 inches. So the correct answer is option O) 24 inches.