Bob$$s utility function was given as U $=($XY$)2$ where X and Y are the quantities of the two different commodities. We derived his demand functions as; X $=$ I $/(2$PX$)$ Y $=$ I $/(2$PY$)$ Bob initially faces prices $$10$ for good X and $$20$ for good Y and earns $$240$ each week. Suppose that price of X then falls to $$6.$ a$.$ Calculate the SE and IE of the price change. b$.$ Calculate the compensating variation of the price change. c$.$ Calculate the equivalent variation of the price change.