a 9-inch candle burns down in 12 hours. at what rate does the candle burn, in inches per hour?

Explanation:

Step1: Determine the formula for rate

Rate = $\frac{\text{Total length}}{\text{Total time}}$

Step2: Substitute the values

Here, total length is $9$ inches and total time is $12$ hours. So rate = $\frac{9}{12}$

Step3: Simplify the fraction

$\frac{9}{12}=\frac{9\div3}{12\div3}=\frac{3}{4}$

Answer:

$\frac{3}{4}$ inches per hour