i really need help because I have a FINAL EXAM ON MONDAY and i so confuse with this question. please HELP me!!

Question

type of vehicles   numbers of vehicles

      car           =            6

    truck          =           10   

    SUV           =           14

  Minivan        =           15

 

1)  At this rate, how many minivans would pass Luann if 60 vehicles passed her?

2)  At this rate, how many trucks would pass Luann if 90 vehicles passed her?

3)  If 150 vehicles passed Luann, how many more minivans than cars would you expect to pass her? Assume the rate continues.

4)  Luann predicted that if a certain number of vehicles passed her by, 42 of them would be SUVs. What was that certain number of vehicles she had in mind?

Answer 1

6+10+14+15 = 45

 

1). if 45 vehicles passed her, 15 are minivans

 

     So, 15/45 = x/60   45x = 900   x = 20 minivans

 

2). if 45 vehicles passed her, 10 were trucks

 

     So, 10/45 = x/90    45x = 900   x = 20 trucks

 

3). Let x = number of minivans if 150 vehicles pass

 

     Then, 15/45 = x/150     45x = 2250     x = 50 minivans

 

     let y = number of cars if 150 vehicles pass

 

     then, 6/45 = y/150     45y = 900   y = 20 cars

 

     There are 30 more minivans than cars if 150 vehicles pass

 

4).  let x = number of vehicles that pass when the number of SUV's is 

      42.

 

      Then, 42/x = 14/45     14x = 1890    x = 135 vehicles