Anyone know any of these?

Nine more than four times a number is the same as one less than twice the number. find the number?

Aplane intersects a pris paralel to the base of the prism. the cross section is a polygon wth eight sides. how many sides does the base of the prism have? a. 10 b. 8 c. 7 d. 9

Amachine part consists of a half sphere and a cylinder, as shown in the figure. the total volume of the part is π cubic inches.