how could I have solved this problem better?

[abcdefg]

JASON'S SALARY AND KAREN'S SALARY WERE EACH P PERCENT GREATER IN 1998 THAN IN 1995. WHAT IS THE VALUE OF P?

1. IN 1995 KAREN'S SALARY WAS 2,000 GREATER THAN JASON'S
2. IN 1998 KAREN'S SALARY WAS 2,400 GREATER THAN JASON'S

GMAT-PREP (DATA SUFF)

This question took me a while to answer. I solved it by writing out the equations as follow:

1. J + 2000 = K -> insufficient.
2. pJ + J + 2440 = pK + K -> insufficient.

However if we subtract step 1 from step 2 then we get:
pJ + 440 = pK. Then we do substitution of K with J.
pJ + 440 = p(J+2000).
pJ + 440 = PJ + p2000.
440 = p2000.
p= 440/2000.

As you can see this took quite a few steps. I'm wondering if there is any cues that i'm missing that would allow me to solve this problem quicker.

[DanaJ]

The only problem here is that you're making a common mistake in solving DS questions: actually solving the problem instead of simply realizing if the DATA IS SUFFICIENT or not.

1. J + 2000 = K - so K - J = 2000

2. pJ + J + 2440 = pK + K --- group accordingly to K - J above to get:

p(K - J) = 2440 - (K - J) and here you STOP and pick C, since you know K - J and therefore can solve the problem.

[ghacker]

This is a DS questions , hence we are not told to solve the question ,but told to check whether the given conditions are sufficient .

So its a logical problem

Logic tells you that the ans = C