If the selling price is Rs.1680 there is a loss of 16%, what should be the marked price on this product, if after allowing discount of 8% there is a profit of 15%?

  loss  = 16%.

let cp = 100 then Selling Price (SP) = CP - Loss = 84

As SP 1680given , the CP would be 

1680 = 84

100 = 2000

cp = 2000

He wants to earn a profit of 15%.

His profit will be $$\frac{15}{100}$$\times 2000=300

Therefore his SP s 2000+300=2300

But he wants to offer a discount of 8%.

SP will be 92 if the Marked Price was 100 and discount was 8%.

With SP being 2300, Marked Price should be $$\frac{2300}{92}$$\times 100= 2500

Marked Price = Rs. 2500