Three friends put money together for a farewell gift. Bhavna puts in 30% of the total, Chetan puts in 40% of what is left after Bhavna's share, and Dinesh puts in the remaining ₹8,400. How much does Chetan put in?

Take the total as 100. Bhavna = 30, leaving 70; Chetan = 40% of 70 = 28; Dinesh = 100 - 30 - 28 = 42. So 42% of the total is ₹8,400 and the total is ₹20,000, making Chetan's share 28% of 20,000 = ₹5,600. Check: 6,000 + 5,600 + 8,400 = 20,000. ₹8,000 is 40% of the total, taking Chetan's rate on the whole instead of on the ₹14,000 left. ₹6,000 is Bhavna's share, and ₹3,360 is 40% of Dinesh's ₹8,400.