The printed price of a book is ₹ 320. A retailer pays

The printed price of a book is ₹ 320. A retailer pays ₹ 244.80 for it. He gets successive discounts of 10% and an another rate. His second rate is :

First discount = 320 ×	10	= ₹ 32
	100

∴ Price after first discount = 320 – 32 = ₹ 288
If the second discount be D %, then

∴	288 × D	= 288 − 244.80 = 43.2
	100

⇒ 288 x D = 43.2 x 100

⇒ D =	43.2 × 100	= 15%
	288

Alternate method to solve this question :
Here, M.P. = Rs. 320, S.P. = Rs.244.80, D₁ = 10%, D₂ = ?

S.P. = M.P.		100 − D₁			100 − D₂
		100			100

⇒ 244.80 = 320		100 − 10			100 − D₂
		100			100

2448000	= 100 − D₂
320 × 90

100 − D₂ = 85
⇒ D₂ = 100 − 85
⇒ D₂ = 15%