If he consumed 6 liters in two days, that would mean he would have consumed 3 liters per day. You would divide 12 by 3, since he drinks 3 liters per day, and after 4 days, he would have consumed 12 liters.
So for this I would set up a ratio. 1/10=x/380 then you cross multiply so 1x380=10x. Then solve the equation so 380/10=x and you get 38in. Hope my explanation helped!
