The Monthly Cost C of Running the Machinery in a Factory

Multiple Choice

The monthly cost C of running the machinery in a factory for t hours is given by $C ( t ) = 10 t + 150.$ The number of hours t needed to produce x products is given by $t ( x ) = 9 x.$ Find the equation representing the cost C of manufacturing x products.

A) $C ( x ) = 90 x + 150$
B) $C ( x ) = 90 x + 1500$
C) $C ( x ) = 19 x + 150$
D) $C ( x ) = 19 x + 160$
E) $C ( x ) = 10 x + 159$