.Total product of an input refers to total volume of goods and services produced by a firm with the given inputs during a specified period of time

Average Product of an input is per unit product of variable factors. It is calculated by dividing the total Product by the units of variable factor.
Average product = \(\frac { Total\ product }{ Unit\ of\ variable\ Factor } \)

Marginal Product of an input is an addition to the total product when an additional unit of a variable factor is employed.
MP = \(\frac { Change\ in\ output }{ Change\ in\ input } ={\triangle q\over \triangle L}\)

The Law of diminishing marginal product states that when we applied more and more units of variable factor to a given quantity of fixed factor, total product increases at a diminishing rate and marginal product falls.

The law of variable proportion states that as we increase the quantity of only one input, keeping other inputs fixed, the total product increases at an increasing rate in the beginning, then increases at decreasing rate and after a level the output ultimately falls.

The law of variable proportion states that as we increase the quantity of only one input, keeping other inputs fixed, the total product increases at an increasing rate in the beginning, then increases at decreasing rate and after a level the output ultimately falls.