Question 12 The traffic flow rate (cars per hour) across an intersection is r(t) = 300 + 900t -240t', where t is in hours, and t=0 is 6am. How many cars pass through the intersection between 6 am and 7 am? CarsQuestion 13 19 A company's marginal cost function is where x is the number of units. Find the total cost of the first 64 units (of increasing production from *=0 to x=64) Total cost: 53.4 Score: 0/7 0/7 answered Question 1 Evaluate the integral I'(25 - 8) "dr by making the substitution u = 1" - 8. + C NOTE: Your answer should be in terms of x and not u.3.4 Score: 0/7 0/7 answered . Question 2 Evaluate the indefinite integral. 6dr x In(4) + C