3. D and E are points on side AB and AC of ?ABC. DE is parallel to BC. If AD:DB = 2:5 and area of ?ADE is 8 cm sq, what is the area (in sq cm) of quadrilateral BDEC?
7. A crate of egg holds one rotten egg out of every 25 egg in it. If 5 out of 8 rotten eggs are unusable and there are total 10 unusable eggs in the crate,then calculate the number of eggs in the crate.