A line segment AB of length 10 meters is passing through the foot of the perpendicular of a pillar, which is standing at right angle to the ground. Top of the pillar subtends angles tan^{–1} 3 and tan^{–1} 2 at A and B respectively. Which of the following choice represents the height of the pillar?
Angles of elevation of the top of a tower from
three points (collinear) A, B and C on a road
leading to the foot of the tower are 30°, 45°
and 60° respectively. The ratio of AB and BC is