I wonder what kind of questions are yes-no data sufficiency? How can i tell if a questions is a regular data sufficiency question or yes-no data sufficiency. I cannot tell!!!

You can tell the type of a Data Sufficiency question by the information they ask before the question mark.

If the question starts the word "is", then its usually a yes/no question. You look at the question stems (1 & 2) to determine whether the answer is YES or NO. What you want is to find a situation where X is either always Yes or always No to determine sufficiency. See the example below and tell me the answer.

Example that I'm making up:

X is an integer, Is X>0?

1) X + 1 = -5

2) X = -6

One easy way to discern them: how would you answer the question? By saying, "Yes?" "No?" Then you have a Yes/No question.

Examples: Is p a positive number?, Are x and y integers?, Can k be expressed as the product of two integers?, etc.

The other type is a "value" question. The only way to answer it is by giving a value.

Examples: What is q? At what time will he run out of gas? How many green balls are there?, etc.

Rey