The ratio of the measure of an exterior angle of a triangle to the measure of the adjacent interior angle is 2: 4. Find the exterior angle and interior angle.

The correct answer is: Exterior angle=60, interior angle=120

An exterior angle and its adjacent interior angle are supplementary angles, so they add to 180°.
The ratio of the measure of an exterior angle of a triangle to the measure of the adjacent interior angle is 2: 4. 
Let the exterior angle be 2x and adjacent interior angle 4x

By property :
2x + 4x = 180
6x =  180
x =  30
The exterior angle is = 2x = 2   30 =  60 and the adjacent interior angle is 4x = 4   30 = 120
Thus, option c is correct : Exterior angle=60, interior angle=120