inequality and field trip

Mrs. william is deciding between two field tips for her class. the science center charges $135 plus $3 per student. the dino discovery museum simply charges $6 per student. for how many students will the science center charge less than the dino discovery museum?

Let x be the number of student going to the field trio.


Cost = fixed cost + variable cost


Cost for the science center


Fixed cost = 135


Variable cost = 3 × x


Cost = 135 + 3x


Cost for the dino discovery


Fixed cost = 0


Variable cost = 6x



The science center will charge less than the dino center if



135 + 3x < 6x


135 + 3x - 3x < 6x - 3x


135 + 0 < 3x


135 < 3x


Divide both sides by 3


135 / 3 < 3x / 3


45 < x


x > 45


The science center will charge less than the dino center if the number of students going is bigger than 45