9. if a prism and pyramid have congruent bases and equal altitudes, then the volume of the pyramid is a. equal to the volume of the prism b. one-third of the volume of the prism c. one-half of the volume of the prism d. three times the volume of the prism

The general rule is that

Volume of Pyramid = (1/3)*(Volume of Prism)
Or
Volume of Pyramid = (Volume of Prism)/3

Which is why the answer is choice B) one third of the volume of the prism

side note: we can multiply both sides by 3 to get
Volume of Prism = 3*(Volume of Pyramid)
The prism and pyramid must have the same base and altitude

Hello sorry can’t good luck tho