# question sentence asking for y when x<y

x must be at least less than 0.5 (i.e., x<0.5).

where 0.5 is the specific answer I am looking for, what is the proper question?

x must be at least less than what value?

does not sound like a proper sentence. "What is the maximum possible value for x?" does not work because x cannot be 0.5.

I also feel "at least" is used improperly here but "x must be less than what value?" cannot work (whether grammatically or otherwise) because for this question 0.4 is a correct answer, but I want it to be wrong.

• You are right. at least is at best redundant, and probably confusing. – user3169 Jan 10 '18 at 3:55

x must be less than what value? is a proper, valid, question for an answer of x must be less than 0.5.

You have said that it cannot work because 0.4 would be a correct answer, but 0.4 would not be a correct answer as all values between 0.4 and 0.5 are in your range of allowed values, so x can be less than 0.4 but x could also be greater than 0.4.

There is nothing wrong with:

x must be less than what value?

But if you're looking for alternative ways of asking the same:

• What is the exclusive upper bound of x?
• For what minimum value of x is x no longer valid?
• x cannot equal or exceed what value?

But honestly I believe your version is the most concise. Sometimes when you're dealing with less than or equal to or greater than or equal to, it is easier to express yourself by describing the opposite case (in this case, rather than specify at what value of x is no longer valid and beyond, specify under which value x is valid as in your example).