If $j$ and $k$ are inversely proportional and $j = 16$ when $k = 21$, what is the value of $j$ when $k = 14$?
I know that inverse proportionality means that the product of $j$ and $k$ is always constant. So, I can use that to find the constant by plugging in the given values of $j$ and $k$: $16 \times 21 = 336$. Now, I can use this constant to find $j$ when $k = 14$: $j \times 14 = 336$. Dividing both sides by 14, I get $j = \frac{336}{14} = 24$. 