Official SAT study guide's answer explanations?

Test Preparation SAT Preparation
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<p>1) That’s too easy…so you shouldn’t have got that wrong.
2) The answer to that had been explained before: <a href=“http://talk.collegeconfidential.com/sat-act-tests-test-preparation/99391-help-collegeboard-blue-book-math-problem.html#post1256608[/url]”>http://talk.collegeconfidential.com/sat-act-tests-test-preparation/99391-help-collegeboard-blue-book-math-problem.html#post1256608&lt;/a&gt;&lt;/p&gt;