How to say I ran out of time?
For example I want to say :
In the exam, I ran out of time
or I lacked in time ?
-The exam was going well but I lacked of time.
my point is : I want to say the time was not enough for me to answer all the questions

Question

Answer

I ran out of time
This is the usual way to say it

Answer

You already have the correct answer: I ran out of time. Your sentences using 'lack' aren't right.

Another option would be to say 'you didn't have enough time' e.g. I didn't have (enough) time to answer all the questions.

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I ran out of time.

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You say, I ran out of time.

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I didn't have time to answer all the questions.

This phrase should do it. The way you said it also sounds good enough.