Line segment AB is parallel to line segment CD. AD intersects BC in E. If lengths of AE, BC and ED are 12 cm, 12 cm and 18 cm respectively, what is the length of EC?
In a class of 60 students there are 33 girls. The average weight of these girls is 62 Kg and average weight of the full class is 66.5 kg. What is the average weight of the boys of the class?
A car travelling at an average speed of 72 km/hr takes 9 minutes to travel a certain distance. By how much should it increase its speed (in km/hr) to travel the same distance in 8 minutes?
In an army selection process, the ratio of selected to unselected candidates was 9:2. If 80 less had applied and 20 less selected, the ratio of selected to unselected would have been 5:1. How many candidates had applied for the process?
ABCD is a quadrilateral inscribed in a circle (radius = ). The bisectors of the angles DAB and BCD intersect the circle at X and Y, respectively. What is the length of the straight line XY?