The answer sheet saying #11 = 3, and #12 = 2 is correct.
With #11, the question asks what the mother makes son do every day (with emphasis on 毎日).
The audio says:
食事の後は必ず、自分が使ったものを洗わせます。
休みの日だけは部屋の掃除をさせます。
So she makes her son wash his own dishes (#3) every day after meals, but clean his room (#2) only on his days off from school.
With #12, the question is what classroom people who have a little bit of experience using computers (コンピューターを少し使ったことがある人) should go to.
The audio at one point says 少し使ったことがある人はこのままこの教室にいてください。, i.e. telling people who fit the description in the question to stay in this classroom (where they are now).
The man never explicitly says the words 202番の教室, but before the line above he had said that beginners should go to となりの201番の教室, so you can infer that the room they're in now is next door, i.e. Room #202. (Also because after that he tells people who can do more various complicated things with computers to go to Room 203 and 204.)