In a group of people solicited by a charity , 30% contributed TK. 40 each, 45% contributed TK. 20 each and the rest contributed TK. 12 each . What percentage of the total contributed came from people who gave TK. 40 ?

Correct Answer: 25%
Let, total participant = 100 30% contributed = 40×30% = 40×30/100 = 12 Tk. 45% contributed = 20 × 45 % = 20×45/100 = 9 Tk.  Test = { 100 - ( 30 + 45) }% = 25% contributed = 12×25/100 = 3 Tk. The percentage of total amount came from people who gave Tk 40 each = 12 /( 12 + 9 + 3) ×100 = 50%