Consider the accompanying cash$-$flow diagram.

a$.$ If $P=$$$1,000,A=$$$200,$ and $i\%=12\%$ per year, then $N=?$

b$.$ If $P=$$$1,000,A=$$$200,$ and $N=10$ years, then $i=?$

c$.$ If $A=$$$200,i\%=12\%$ per year, and $N=5$ years, then $P=?$

d$.$ If $P=$$$1,000,i\%=12\%$ per year, and $N=5$ years, then $A=?$