The problems you describe are very common for DS, that's why DS problems are set up that way
First, are you brushed up on general math skills? Good quant problem solving skills are necessary to be able to look at a problem and know/figure out what the first step is.
Second, have you read the strategy on DS (see strategy link in my sig and also this gmat-math-book-87417.html
)? When you're dealing with DS problems that are roughly ~650 level score and below, you can use the DS strategy fairly effectively. Once you get into more difficult problems, it becomes less useful.
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