30-9

Answer E.

Let's consider two situations that each satisfy both statements together:

If BAD=ADC=90, and ABC=2*BCD, BCD would indeed equal 60.

If DAB=ABC=90, BCD=45 (ABC=2BCD) and ADC=135. No angle would equal 60.

I thought E as well but the answer is C....


Can anyone help us?

The answer you have must be incorrect. I had this question in GMATPrep and the answer was indeed E.

Hi,
the Answer E is correct.
The total of the four angles of the quadriateral is 360 degrees.
If two angles are right angles, i.e. these two sum up to 180 degrees.
Then remaining two would sum upto: 360 -180 = 180 degrees.

If these are in the ratio of 1 & 2 then the angles must be 60 & 120 degrees, viz., one angle is 60 degrees.
Hence Both together are sufficient but not alone.

Hmm. I first thought E as well, but now I think the answer can be C...

from 1) + 2) 180 + x + 2x = 360

3x = 180

x=60 ??


Dose anyone else see this question before and know the answer?

You forget the case under which the 2x=90 and x=45.

Yes you are correct Beny. there are two solutions:
45, 90, 90, 135 &
60, 90, 90, 120.

My bad, I missed the first case in the analysis.

Thanks for correcting.