This endorsement is required if the driver will pull two or three trailers. To receive this endorsement, applicants must pass a test The test consists of 20 multiple choice questions. Each question has four answer choices. To pass, the applicant must answer at least 16 questions correctly. Test questions come from the Texas Commercial Motor Vehicle Drivers Handbook. Questions come from chapters covering: Driving Safely, Air Brakes (if applicable), Combination Vehicles and Doubles and Triples. The Double/Triple endorsement can be used with the Class A CDL.