Help me with these four questions and thanks

45 was divided by a power of ten to get 4.5. what power of ten was it divided by? people 4.5

The cross-sectional areas of a right triangular prism and a right cylinder are congruent. the right triangular prism has a height of 6 units, and the right cylinder has a height of 6 units. which conclusion can be made from the given information? the volume of the triangular prism is half the volume of the cylinder. the volume of the triangular prism is twice the volume of the cylinder. the volume of the triangular prism is equal to the volume of the cylinder. the volume of the triangular prism is not equal to the volume of the cylinder.

Agallon of apple juice cost $7 a pack of eight 4.23oz box of apple juice $2.39 which is a better deal