Context: At a minimum, HDTV has twice the linear resolution of standard-definition television (SDTV), thus showing greater detail than either analog television or regular DVD. The technical standards for broadcasting HDTV also handle the 16:9 aspect ratio images without using letterboxing or anamorphic stretching, thus increasing the effective image resolution.

Question: At least how many times more linear resolution does HDTV have over SDTV?
Answer: twice

Question: HDTV increases the effective image resolution by not using what?
Answer: letterboxing or anamorphic stretching

Question: What does SDTV stand for?
Answer: standard-definition television

Question: HDTV handles what aspect ratio without using letterboxing or anamorphic stretching?
Answer: 16:9

Question: At least how many times more linear resolution does SDTV have?
Answer: Unanswerable

Question:  HDTV increases the effective image resolution by using what?
Answer: Unanswerable

Question:  What does HDTV stand for?
Answer: Unanswerable

Question: SDTV handles what aspect ratio without using letterboxing or anamorphic stretching?
Answer: Unanswerable