The correct option is A ₹2500
Let the cost price for A be x
Now, loss suffered by A is 20% and the money paid by B will be the selling price for A
So, SP=₹2000
Now, loss% = CP−SPCP×100
20= x−2000x×100
1 = x−2000x×5
x = 5x - 10000
4x = 10000
x = 2500
So, cost price of the radio for A is ₹2500