Question 856225
We know the number of cars is between 33 (one car for each family) and 99 (3 cars for each family).
It can't be 33 since one car families (o) equals three car families (t)
33 cars total means  zero families own three 
Remember each family owns at least one.
o=t
f=33
The problems doesn't say how many own two cars.
16 own 1 16 own 3 and one owns 2. 33 families 

15*1+15*3+3*2 =66
14*1+14*3+5*2 =66 
13*1+13*3+7*2=66
12*1+12*3+9*2=66
11*1+11*3+11*2= 66 my favorite 
10*1 +10*3+13*2=66
9*1+9*3+15*2 =66

It appears that the total is always 66