Value of m varies directly as value of n and n=5 when m=12. what is n when m=18?

Customers at an ice-cream shop took a survey .the results showed that 144 customers rated the shop as being "very satisfactory ."this number represented 45%of the total nunber of customers who took the survey

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.

Solve the following pair of equations for x and y: ax/b_ by /a= a +b; ax - by = 2ab