The difference between a discount of 30% and two successive

The difference between a discount of 30% and two successive discounts of 20% and 10% on the marked price of an article is Rs. 144. The marked price of the article is

Let the marked price of article be Rs. M.

Single equivalent discount for X % and Y % =		x + y −	xy		%
			100

Single equivalent discount for 20% and 10% =		20 + 10 −	20 × 10		% = 28%
			100

According to the question,

30% of M – 28% of M = 144

⇒	M × 2	= 144
	100

⇒ M =	144 × 100
	2

⇒ M = Rs. 7200