Cost price of article A is ₹ 200 more than the cost price of article B. Article A was sold at 10% loss and article B was sold at 25% profit. If the overall profit earned after selling both the articles is 4%, then what is the cost price of article B?

Let, cost price of article B be ₹ x

So, cost price of article A = ₹ (x+200)

So, selling price of article A = ₹ $$(x+200)\times\ 0.9=0.9x+180$$

Selling price of article B = ₹ $$1.25x$$

So, total selling price = ₹($$1.25x+0.9x+180$$) = ₹($$2.15x+180$$)

Also, overall profit = 4%

So we can say, ($$2.15x+180$$) = $$1.04\left(x+x+200\right)$$

or, $$2.15x+180=2.08x+208$$

or, $$2.15x-2.08x=208-180$$

or, $$0.07x=28$$

or, $$x=\dfrac{28}{0.07}=400$$

So, cost price of article B = ₹400