The Official Guide For GMAT® Quantitative Review, 2ND Edition
What is Ricky's age now?
(1) Ricky is now twice as old as he was exactly 8 years ago.
(2) Ricky's sister Teresa is now 3 times as old as Ricky was exactly 8 years ago.
Statement 1) r = 2(r-8), definitely r can be determined - Sufficient.
Statement 2) s = 3(r-8) , we don't know s, we cannot determine r. Not Sufficient.
Hence Option A)
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