Determine whether the following changes in the demand for loanable funds and the supply of loanable funds will raise the real interest rate, lower the real interest rate, leave the real interest rate unchanged, or have an ambiguous effect on the real interest rate:
a. Increase in the supply and an increase in the demand.
b. Increase in the supply and a decrease in the demand.
c. Decrease in the supply and a decrease in the demand.