Answer:
volume of cone is 8 cubic inches.
Explanation:
We have been given that volume of cylinder = 24 cubic inches.
Since, cone fits exactly inside of the cylinder hence, we have
Volume of cylinder = volume of cone
Now, we know the formula
Volume of cone = 

Volume of cylinder = 

Now, we have been given that 
 

Therefore, we have
Volume of cone is given by
 

Hence, volume of cone is 8 cubic inches.