...attached are 4 questions from the GMAT prep, i got really beaten up by. Any assistance to would be very much appreciated
I will respond to the first two. I have seen the other two on this forums, so please do a search.
bdc = 2x.
Therefore, abd = 180 - adb - bad = 180 - (180-2x) - x = x.
Therefore, ad = bd.
Now, bd = bc (since bdc = bcd = 2x.
Therefore, bc = ad.
St.1: ad = 6.
Therefore, bc = 6. SUFF.
St. 2: x = 36.
No info any of the lengths. Insuff.A.