These problems can get really confusing so I always like to think of them in terms of a prime "box" filled with the prime factors, and which prime factors can or cannot belong in it! (MGMAT strategy!)
The question rephrase -- does K have at least 2 two's in it's prime box?
In statement 1, we are told that 8k is divisible by 16. That means 8k has a prime box with 2,2,2,2 (all the prime factors). But these 2's can belong to 8 or to K- we don't know! Insufficient.
In statement 2, we are told that 9k is divisble by 12. So 9k's prime box has a 2, 2, and a 3. But the 2's can only belong to K, because 9 doesn't have any 2's as prime factors. So we have --- sufficient!
