If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

# GMAT: Data sufficiency 14

63-68, pgs. 282-283. Created by Sal Khan.

## Want to join the conversation?

• Problem #67: Statement no. 1: AB+CD+AC+BD=6
AB+BD=6-CD-AC => B(A+D)=6-C(D+A) => B(A+D)=6-C(A+D) => B=6-C =>B+C=6
someone please correct me if I am wrong, but isn't statement no.1 alone sufficient or did I solve the equation wrong?
• You forgot to divide 6 on the right hand side by A+D.
• To download a video, go to Info (underneath the video) > Download this lesson.
• At time , question 65 part 2. Sal identifies X as odd. Why did Sal decide odd, why not even? Can you designate X as even? If not, why not? if you can, the statement would be insufficient...Help.
• Question 65 states that M/2 is not an even integer. This means that M/2 could be an odd integer, could be a fraction, could be an irrational number, in fact it could be anything EXCEPT for an even integer. Therefore the only thing that M can't be is an even integer, because any even integer divided by two will be an even integer. Therefore by deduction M must be an odd integer.

The ONLY way for M/2 to be an even integer is if M is an even integer. Therefore because M/2 is not an even integer M has to be non-even which means it has to be odd.

Anyone agree with this logic??