Data Sufficiency

Hello,

Can you please tell me if my solution is correct:

The value of a rare baseball card A appreciated by 20 percent over a five year period; over the next five years, the value plummeted by 50 percent. Over the same total time period, the value of another card B increased by 100%. At the end of ten years, the reduced value of A was what percent of the increased value of B?

1.Card A's initial value was $1000.
2.The initial value of A was four times that of B.

OA: B

Let Card A's initial value be a.
After 5 years, A's value is 1.2a
After the next 5 years, A's value is 0.6a

Let Card B's initial value be b
After 10 years, B's value is 2b

Hence,
0.6a - 2b
? - 100

=> 0.6a x 100 = ? x 2b
=> ? = (0.6a x 100)/2b

1) In-suff.

2) a = 4b

So, ? = (0.6 x 4b x 100)/2b = ( 2.4 x 100 )/2 = 120

Hence, card A's value is 20% more than card B's value.


Thanks a lot,
Sri

From the stem, you know that you're comparing .6A to 1.2B. If A=4B, simply plug in for A:

.6A = .6(4B) = 2.4B

2.4B is 200% of 1.2B.

Statement 2 gives you A in terms of B. Let A=20 and B = 5.

.6A = .6*20 = 12

1.2B = 1.2*5 = 6

12 is 200% of 6.