Bunuel wrote:
A squirrel climbs a straight wire from point A to point C. If B is the midpoint of AC, how far above the ground is point B?
(1) Point C is 40 feet above the ground.
(2) x = 60
Kudos for a correct solution.Attachment:
squirrelonwire_figure.PNG
Use the midpoint theorem we studied in school/college.
In the triangle provided consider the points from B&C hitting the ground as D&E.
Hence we have two triangles -> ACE & ABD. Since B is the midpoint of AC and CE||BD from the midpoint theorem we know that D is the midpoint of AE and also CE=2BD.
Actually, the midpoint theorem stems from the concept of similar triangles and all the sides in the 2 triangles will be in the ratio 1:2
hence CE = 2BD, AC = 2AB = 2BC, AE = 2DE = 2AD
So we can conclude if we know any one of the sides we can know the corresponding side of the other triangle. Here we know CE and hence can calculate BD.
Hence A is the correct answer.