Question 6 The traffic flow rate (cars per hour) across an intersection is r(t) = 400 +600t - 120t', where t is in hours, and t=0 is 6am. How many cars pass through the intersection between 6 am and 10 am? Cars. Question 7 20 A company's marginal cost function is where x is the number of units. Find the total cost of the first 36 units (of increasing production from x=0 to x=36) Total cost: 5. Question 8 Evaluate the indefinite integral I' + 2 +0