What will be the effect of the following changes in Total Revenue on Marginal Revenue?

What will be the effect of the following changes in Total Revenue on Marginal Revenue?
(i) Total Revenue increases at a decreasing rate.
(ii) Total Revenue increases at a constant rate.

(i) Total Revenue increases at a decreasing rate, when Marginal Revenue falls but remains positive.
(ii) Total Revenue increases at a constant rate a when Marginal Revenue is constant and equal to Average Revenue.