Asian 's way of learning tenses.......

Recently, or maybe not just recently, I have come across too many tenses questions set by the Malaysian Chinese Independent School teachers. I totally do not agree with their verb form questions allow only a presumed answer.

Eg:
A few pages have been torn from the book. > What's wrong with a few pages are torn from the book.
(Frankly, I do not see why "are torn" cannot be accepted, there is only a slight difference of meaning. Who says that we can't express the sentence as a piece of fact)

You will have been informed of the programme by tomorrow. (the teacher insists "will have been informed is the only valid answer, i seriously do not see why we can't say

You will be informed of the programme by tomorrow. (The only difference in my opinion is that will have been informed implies the person will obtain the confirmation, most likely, before the advent of tomorrow.

Please give me your opinions on whether my ideas make sense. i seriously do not think questions without a clearer context takes only one valid tense.