D and E are points on side AB and AC of ΔABC. DE is parallel to BC. If AD:DB = 2:3 and area of ΔABC is 100 sq cm, what is the area (in sq cm) of quadrilateral BDEC?
A man has some hens and some cows. If the total number of heads of hens and cows together is 50 and the nunber of feet of hens and cows together is 142, then the number of cows is