A man sold an article for ₹390 by first giving a d% discount on its marked price, and then another discount having the same nominal value (in ₹). If the marked price of the article is ₹3900, then what is the value of d?

Correct option is A

 Given: 

The marked price of the article is 3900.

A man sold an article for 390

First giving a d% discount on its marked price

Formula used: 

$$Discount = \frac{d}{100}\times 100$$ 

Solution: 

$$First \ Discount = \frac{d}{100}\times 3900 = 39d$$ 

After the first discount,

$$\text{Price after first Discount} = M - 39d = 3900-39d.$$  

After the second discount,

$$\text{Price after second Discount} = ( 3900- 39d) -39d = 3900- 78d$$ 

The final selling price is 390.

$$3900- 78d = 390.$$ 

$$3900 - 390 = 78d$$ 

$$3510 = 78d$$ 

$$d = \frac{3510}{78}= 45$$ 

Thus, the value of ddd is 45.  

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