The change in the optimal quantity of a good when its price changes and the consumer’s income is adjusted so that she can just buy the bundle that she was buying before the price change is called?
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 sq cm, what is the ratio of area of ΔADE: area of quadrilateral BDEC?