Manhattan GMAT CAT- Length of Line DE

[Misterbuff]

Hi everyone,

Please see the attached problem. After reading the explanation Manhattan GMAT provided, I still believe I am correct. I would appreciate it if someone out there is able to provide a better explanation or maybe support my answer (D).

Thanks.

[parallel_chase]

Hi everyone,

Please see the attached problem. After reading the explanation Manhattan GMAT provided, I still believe I am correct. I would appreciate it if someone out there is able to provide a better explanation or maybe support my answer (D).

Thanks.

I think the answer should be B.

Statement I

insufficient because it does not tell us anything about other angles.

Statement II

We can determine that both triangles are similar triangle.
therefore DE= 7

Whats the OA?

[Misterbuff]

Hmm, I just took another look at the problem and I now agree with the answer. Thanks for the help!

[nitin86]

Hi everyone,

Please see the attached problem. After reading the explanation Manhattan GMAT provided, I still believe I am correct. I would appreciate it if someone out there is able to provide a better explanation or maybe support my answer (D).

Thanks.

I think the answer should be B.

Statement I

insufficient because it does not tell us anything about other angles.

Statement II

We can determine that both triangles are similar triangle.
therefore DE= 7

Whats the OA?

@paralle_chase,

Stmt 1 does tell us about the angle A and B. Because CA and CB are the radius of the circle, that mean CA = CB = r. And in triangle, ABC, angle C = x = 60, hence, angale A and angle B is also 60 degree.

Also, by same logic, triangle ABC becomes similar to triangle BDE

[parallel_chase]

@paralle_chase,

Stmt 1 does tell us about the angle A and B. Because CA and CB are the radius of the circle, that mean CA = CB = r. And in triangle, ABC, angle C = x = 60, hence, angale A and angle B is also 60 degree.

True

Also, by same logic, triangle ABC becomes similar to triangle BDE

False, you cant assume that DE = BE

We know that angle B is 60, but we dont know about angle D and angle E. Hence Insufficient.

Let me know if you think otherwise