Given that Ben drinks tea of 3 and 1/2 liters every 2/3 hour, here is how we are going to know how many liters of tea he consumers in an hour. 2/3 of an hour is 20 minutes. So in every 20 minutes, he consumes 3 and 1/2 liters. So let us multiply 3 and 1/2 by 3 and we bet 10 and 1/2 liters. Therefore, he can finish 10 and 1/2 liters of tea in an hour. Hope this answer helps.