Income of 'B' is 20/27 than that of 'A' and the income of 'C' is Rs.2000 less than that of 'B'. 'A' spent 25% of his income and saved the rest, while 'B' spent Rs. 2400 less than what he saved such that the ratio of expenditure of 'A' and 'B' is 3 : 4 respectively if 'C' saves Rs.13600 then how much amount does he spent?