BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

In the \(xy-\)plane above, is angle \(BCA\) greater than 90

Expert replies
by AAPL » Sat Oct 05, 2019 3:59 am
Princeton Review

In the \(xy-\)plane above, is angle \(BCA\) greater than 90 degrees?

1) Points \(A\) and \(B\) have different \(x-\)coordinates.
2) The measure of angle \(B\) is twice the measure of angle \(C\).

OA E
Join the discussion
Source: — Data Sufficiency |

by deloitte247 » Thu Oct 10, 2019 8:51 am
Image

Question=> Is angle BCA greater than 90 degrees.
$$i.e\ is\ \angle C>90^0?$$
Statement 1: Points A and B have different x-coordinates. The x-coordinates of point B have the capability to increase or decrease angle C if it reduces or increases respectively.
So, we cannot assert whether angle C is greater than 90 degrees or not. Therefore, statement 1 is NOT SUFFICIENT.

Statement 2: The measure of angle B is twice the measure of angle C.
$$B^0=2C^0$$
$$C^0=\frac{B^0}{2}$$
$$If\ \angle B=200^0,\ then\ \angle C=\frac{200^0}{2}=100^0;\ C^0>90$$
$$If\ \angle B=120^0,\ then\ \angle C=\frac{120^0}{2}=60^0;\ C^0<90$$
Since we cannot also assert whether angle C is completely greater than 90 degrees or not, then, statement 2 is NOT SUFFICIENT.

Combining both statements together;
No specific coordinates were provided from statement 1 and no values for the angles in statement 2, hence, combining both statements together is NOT SUFFICIENT.
Therefore, option E is the correct answer.

Thanks
Join the discussion