Goals That Would Have Been

In the above question, what would have been the change in current in A if battery were some internal resistance.

If 21st July, 1999 is a Wednesday, what would have been the day of the week on 21st July 1947 ?

A watch Is sold for' 4950 at a gain of 10 % . What would have been the gain, If It had been sold for 4800

A radio is sold for Rs. 880 at a profit of 10%. What would have been the gain or loss percent, had it been sold for Rs. 780 ?