c) A consumer spends whole of his income, Ksh 1000 on two goods, X and Y. The price of good Y is fixed at Ksh 20per unit and it falls to Ksh 10 per unit after a week. The quantity demanded of X is given as a function of its own price and the consumer's income as: x =M/5PX Calculate the substitution and income effects under constant real income hypothesis of Slutsky