Let current quantity in tank = X and Tank's total capacity = T
Now, X - 200 = 3T/7
So, if we know X we could solve for T.
2. Tricky but Suff. Since T - 1600 = 3T/7
GMAT is an addiction and I am darn addicted
Preparation for final battel:
GMAT PREP-1 750 Q50 V41 - Oct 16 2011
GMAT PREP-2 710 Q50 V36 - Oct 22 2011 ==> Scored 50 in Quant second time in a row
MGMAT---- -1 560 Q28 V39 - Oct 29 2011 ==> Left Quant half done and continued with Verbal. Happy to see Q39
My ongoing plan: http://gmatclub.com/forum/550-to-630-need-more-to-achieve-my-dream-121613.html#p989311
Appreciate by kudos !!