Consider commercial properties A and B for which the land value relative to the overall value of the property is $80\%$ and $20\%,$ respectively. Each property is currently valued at $$10$M$.$ a$.$ If during a particular $5-$year period structure prices are expected to increase by $2\%$ annually and land prices are expected to increase by $4\%$ annually, what is the expected value of property A and of property B at the end of this $5-$year period?

b$.$ If during a particular $5-$year period structure prices are expected to increase by $2\%$ annually and land prices are expected to decrease by $4\%$ annually, what is the expected value of property A and of property B at the end of this $5-$year period?