Suppose ABC is a triangle with AB of unit length D and E are the points lying on AB and AC respectiv...........

Quantitative Aptitude (CDS) Height and Distance

Suppose ABC is a triangle with AB of unit length D and E are the points lying on AB and AC respectively such that BC and DE are parallel. If the area of triangle ABC is twice the area of triangleADE, then the length of AD is

$\small \frac{1}{2}\, units$