The length of a model car is 6in, the scale used to build this model car is 1: 35 what is the actual lenght of the model car in feet?

An easy way to solve this problem is to set up a proportion and cross-multiply. 

now cross-multiply, and you get this:

or 

so the actual car is 210 inches, but we need it in feet!
so 
the car is 17.5 feet in length!
Have a good day, and good luck with your homework.