manhattan gmat word translations

[resilient]

in used car lot, there are three times as many red cars as green cars. If tommorow 12 green cars are sold and 3 red cars are added,then there will be 6 times as many red cars as green cars. How many green cars are currently in the lot?

I cant grasp why "there are three times as many red cars as green cars" translates to r=3g . I keep translating it to 3g=r but i dont see why i am wrong? also how does 3+r=6(g-12) translate from "if 12 green cars are sold and 3 red cars are added, there will be 6 times as many green ones"..

any help? also where could I go for translation tutorial?

[meghamehta15]

hey seems like ur translation is right...

g= green cars
and r= red cars

r=3g

6(g-12) = 3+r
6g-72=3+3g
3g=72
g=25

Is 25 green cars the right answer?