please show work

A. The ER is real' $.10, or $10 buys 1 real. The change in the ER is what percentage wise, if at the end of the year the ER is I$.011111111, or $90 buy real 1 ? Show it in two ways. The one is real per dollars and the other is dollars per real. B. The Nigerian naira versus the US dollar is 7 to 1 , i.e., 7 naira buy one dollar. The ER between the Swiss franc and the US dollar is one Swiss franc to 1.1 US \$. Finally, the naira trades 7.02 per one Swiss franc. What kind of triangular arbitrage will induce a profit for you? Assume you start with $1 million