D and E are points on side AB and AC of ΔABC. DE is parallel to BC. If AD:DB = 2:5 and area of ΔADE is 8 cm sq, what is the area (in sq cm) of quadrilateral BDEC?
AB is a chord of the circle and its center is “O”. ON is perpendicular to AB. If the length of AB=20 cm, ON-(2√11) cm, find the radius (in cm) of the circle.
If a young son works quickly for 2 hours and prepares 16 items in a day, and his old father works slowly for 8 hours and prepares 24 items in a day, which of the following is true?