Mae used the rule "divide the length 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 wood that requires 7 nails? 18 inches 21 inches 24 inches 27 inches

Answer 1

According to Mae's rule, the number of nails needed is calculated by dividing the length of the wood by 3.

Let's verify the calculations with the examples given:

1. For a piece of wood that is 9 inches: \[ \text{Number of nails} = \frac{9 \text{ inches}}{3} = 3 \text{ nails} \]

2. For a piece of wood that is 39 inches: \[ \text{Number of nails} = \frac{39 \text{ inches}}{3} = 13 \text{ nails} \]

Both calculations are consistent with Mae's rule.

Now, we need to find the length of wood that requires 7 nails: \[ \text{Length of wood} = \text{Number of nails} \times 3 = 7 \times 3 = 21 \text{ inches} \]

Thus, the length of wood that requires 7 nails is 21 inches.