The first trick is to understand how to approach DS.

First simplify the stem. Problems often have complicated stems that are much easier to work with once simplified.

Then, determine what information you would need to answer the question.

Once you thoroughly understand the stem look at the first statement. If it gives you the answer you need, the response is narrowed to A (1 only) or D (both). If it is not sufficient then your answers must be B (2 only, C (together)or E (not enough information).

Then look at the second statement. If it is sufficient, you are done.

If both statements are insufficient, you need to combine them, treating them as a single statement. Note that you only have to combine statements if EACH is insufficient by itself.