Easy way to sort through DS problems logically

[GaStateMTAX]

Hi everyone,

For those of you having trouble getting lost in the DS problems I noticed something the other day while solving them that helps immensely.

I noticed that you can split DS problems into a AD/BCE type split.

For example:

How much did a telephone call cost?

1. The call lasted for 53 minutes
2. The cost for the first 3 minutes was 5 times the cost for each additional minute.

So, start by writing this down on your sheet of paper (or on test day your dry erase):

AD/BCE
1.
2.

First, think about what you need: you'll need the cost per minute, how long the call was or maybe the total cost of the call.

Next, look at number 1. It gives you the length of the call. Great. But it doesn't help us here because we don't know the cost per minute. So on your handy little split chart put an "X" next to number 1 and cross out A and D. Like this:

XX/BCE
1.X
2.

Now check number 2. Nope it doesn't help us. It gives a little more information but without the cost for the first 3 minutes or the cost for each additional minute we can't solve anything. Cross out B.

XX/XCE
1.X
2.X

Now test "C". Neither 1 or 2 satisfy the sufficiency test because neither give us a cost. Cross out C.

The answer is therefore E.

Rather than "solving" each problem, you essentially just eliminate until there is only one possibility. This also saves me a lot of time, I can pop them off like popcorn now! I just thought I share with you all this helps me compartmentalize DS problems and helps me focus a little better. Especially since I am a graph person.

[ccrocnyc]

extremely helpful strategy. Thank you.

[BrianSmith]

Another tip:

If you don't know exactly what you need, try to go the other way: try to find two possible different answers to prove the statement insufficient. (It's only sufficient if it gets you a single clear answer)

Remember, you don't actually need to know the answer in DS, only if the statements are enough.