Step-by-step explanation:
Since, the grid only has 100 squares, and the total number of cars is 180, you have to make a proportion.
(27 of the 180 cars are minivans. x of the 100 cars are minivans.)
Now, you cross multiply. 180 times x is 180x
100 times 27 is 2700
Now, equal them to each other and solve for x:
To check your answer, plug in 15 for x:
27/180 should equal to 15/100...
...they do!