(i) When MP increases, TP increases at an increasing rate.
(ii) When MP is constant, TP increases at constant rate.
![](https://www.sarthaks.com/?qa=blob&qa_blobid=9746007053714679253)
(iii) When MP decreases, TP increases at a diminishing rate
(iv) When MP is zero, TP is maximum.
(v) When MP is negative, TP declines.