1/3 chance of landing on it twice
The standard equation is y=ax^2+bx+k and the vertex way is y=a(x-h)(x-h)+x
so the coordinate for x is -b/2a, for your problem a=-4 b=-16 so the coordinate for x is -(-16)/(2*(-4))=-2. Now you have to replace x=-2 in your equation y=-4(-2)^2-16(-2)-11= 5.
The vertex is (-2, 5)
So you have a total of 32 + 6 = 38 passengers
only 9 will fit in each, so divide 38 by 9
38/9 = 4.22222222222...
But you will need a whole van for the extra people (the .2222222222....) so you need 5 vans to get all the people in
Problem 1 y= -2x+5 problem 2 y= 2/7x+4
