Answer 1) Discounted price = Actual price - discount
and discount = actual price * discount%
=> discount = 850 * 25/100 = 212.5
So, discounted price = 850 - 212.5 = 637.5
Answer 2) if income means profit then this would be the answer
Let the amount be 2x.
So, (x*10%) + (x*12%) =46,475
x = 211250
So the invested amount = 422500