The list price of a clock is ₹ 160. A customer buys it

The list price of a clock is ₹ 160. A customer buys it for ₹ 122.40 after two successive discounts. If first discount is 10%, the second is

As per given question marked price = 160
After 10% discount, The Selling price

S.P. =	100 - 10	× 160 = ₹ 144
	100

Let us assume the other discount = D%

∴	(100 − D)	× 144 = ₹ 122.40
	100

⇒ 100 − D =	12240
	144

⇒ 100 – D = 85
⇒ D = 100 – 85 = 15%
Alternate method to solve this question :

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

⇒ 122.40 = 160		100 − 10			100 − D₂
		100			100

12240	= 90 ×		100 - D₂
160			100

1224000	= 100 − D₂
160 × 90

12240	= 100 − D₂
16 × 9

1360	= 100 − D₂
16 × 1

⇒ 85 = 100 – D₂
⇒ D₂ = 15%