How much percent more than the cost price should a shopkeeper

How much percent more than the cost price should a shopkeeper mark his goods so that after allowing a discount of 25% on the marked price, he gains 20% ?

Given that , discount = 25% and gains = 20%
Let C.P.of article = 100
If the marked price of article be y, then

y ×	75	= 120
	100

⇒ y =	120 × 100	= 160
	75

⇒ 160 - 100 = ₹ 60 i.e. 60% above the cost price .
Second method to solve this question :
Here . r = 25%, R = 20%

Required percentage =		r + R	× 100		%
		100 − r

Required percentage =		25 + 20	× 100%
		100 − 25

Required percentage =	45	× 100 = 60%
	75