Temple Puzzle

A friend sent me this puzzle. 

A man starts from his house with some money to visit four temples. As soon as he enters temple 1 his money gets doubled. He donates Rs 100 and moves. At temple 2 again his money is doubled and he donates Rs 100. His money is doubled again at temple 3 and he donates Rs 100. At temple 4 again his money gets doubled. He donates Rs. 100 again and returns home empty handed. How much money he had when he started from his house??? 

If you solved the puzzle, then I have two more questions around this puzzle: 

• If the question were changed and there were 5 temples instead of 4 and everything else remaining the same how much money would I have had initially? What if there were 6 temples? 7 temples? How would you solve each of these questions without solving the problem from the beginning each time? 
• If the man had Rs 512 with him and he visited N number of temples at the end of which he had no money, then what is the value of N (the number of temples he visited)? - This question may be difficult since it needs some higher level Maths (Most puzzles in this blog do not need any level of Maths beyond 8th Grade).