Here is a nice drill to help you interpret CR questions.
Please translate each of the following into either: 1) if P then Q form; or 2) P if and only if Q form. (NOTs are allowed)
1) Mark's new company will be successful provided he gets the loan.
P is sufficient for Q
if loan, then successful
if not successful , then not loan
if not loan ,then may or may not be successful
if successful ,may or may not be loan
2) Only if John is allowed to go will Ken go.
if john goes, ken will go
if ken does not go, then john has not gone.
if ken goes, john may or may not have gone
if john does not go, ken may or may not have gone.
3) Give a talented teacher academic freedom, and she will excel.
Academic freedom is both a necessary and sufficient condition for excellence
If academic freedom, then excel
if excel, then academic freedon
if not academic freedom, must not excel
if not excel, must not have academic freedom
4) No Montague is a Rothschild.
If montague, then not rothschild
If not montague, then may or may not be rothschild
If rothschild, then not montague
if not rothschild, then may or may not be montague.
5) Anyone who is not a Montague cannot be a Rothschild.
Montague if and only if Rothschild.
6) All Montagues are Rothschilds.
If Montagues, then Rothschilds
If not Rothchilds, then not montagues
7) Only Montagues are Rothschilds.
If Montagues , then Rothchilds
If not rothchilds, then not montagues
8) A Montague will never attend a party hosted by a Rothschild.
If party not hosted by rothschild, then montague attends.
If party hosted by rothschild, montague never attends.
9) Men and women cannot understand each other.
If men, then they cannot understand women
If women, then they cannot understand men.
10) There is no God but Allah.
If God, then Allah
If not allah, then not god.
11) None but the worthy are saved.
If saved, then worthy
if not worthy, then not saved
if not saved,may or may not be worthy
if worthy, may or may not be saved
12) A score of 750 is necessary to get into MBA University.
if Q ,then P
if not Q, then not P
if 750, may or may not get into MBA univ
If not 750, will not get into MBA univs
13) A score of 750 is sufficient to get into MBA University.
if 750 ,then admit into MBA univ
If not an admit into mba univ, then not 750.
If MBA univ admit, may or may not have 750
If not 750, may or may not admit into mba univ
14) I am going to order either the Fish or the Steak, but not both.
Fish if and only if not steak AND Steak if and only if not fish
if not fish, then steak AND if not steak, then fish.
15) Loyalty to Al Qaeda and America contradict each other
If loyal to alqaeda , then not loyal to america
if loyal to american, then not loyal to alqaeda
If not loyal to america, then may or may not be loyal to alqaeda
If not loyal to alqaeda, may or may not be loyal to america
16) It is both a necessary and sufficient condition for an integer to have N factors of 10 in order to have N trailing zeroes.
if N factors of N, then N trailing zeroes
if N trailing zeroes, then N factors of N
if not N factors of N, then not N trailing Zeroes
if not N trailing zeroes, then not N factors of N.
17) I will flunk the GMAT unless AkamaiBrah teaches me
if not akamaibrah, then flunk gmat
if not flunk gmat, then akamai
if flunk, may or may not be akamai
if akamai, may or may not be flunk