Find the number of vertices of a prism whose cross-section is a 30-sided polygon.

Five dinosaurs go for a walk and come across some lovely chicken wings. their names are rexy, bronto, steggy, paly, and terry. there are exactly 5 dozen wings(equal enough for each dino to have a dozen right? ); however, terry is on a diet and he only eats 6 wings. if paly eats 2 more than terry, steggy eats 4 more than paly, and bronto and rexy eat the same amount because they are really hungry from not eating all day, how many chicken wings did each dino eat?

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

If the value of cos330°is√3/2 then find cos 165°.