SDCAR2010【逻辑入门】(十五)More on Negation
Necessary assumption. Use negation. I said these two sentences hundreds of times here. If you master the technique of negation, you should be able to solve the necessary assumption problems easily and pass GMAT with flying colors.
When you negate an answer, just negate it. Try not to turn it into its opposite. Also, negate either the verb or the quantity, but not both.
To negate an if-then statement, negate ONLY the then clause. So "if A, then B" would become "if A, then not B"