The concept of total product, marginal product and average product is very important in economics. Let us discuss them one by one:

TOTAL PRODUCT (TP): It is the sum total of output produced by all the units of variable factor along with the fixed factors of production.

TP=50+70+80+80+60=340 UNITS OF A COMMODITY (Refer below table)

MARGINAL PRODUCT (MP): It is the addition made to total product by using one more unit of variable factor.

MP= TP_n-TP_n-1

MP= 70-50= 20 UNITS (Refer below table)

AVERAGE PRODUCT (AP): it is the output per unit of variable factor.

AP= TP/L

LABOUR	TOTAL PRODUCT	AVERAGE PRODUCT	MARGINAL PRODUCT
1	50	50/1=50	50
2	70	70/2=35	20
3	80	80/3= 26.67	10
4	80	80/4=20	0
5	60	60/5=12	-20

The above table is showing that the total product is 50+70+80+80+60=340. Average product is calculated by using formula AP= TP/L and marginal product is calculated by using formula MP= TP_n-TP_n-1

Which shows that marginal product is falling then becomes zero and thereafter it becomes negative.

The table shows that: i) as long as MP is increasing the TP is also increasing at increasing rate.

ii) When MP starts diminishing, TP increase at diminishing rate.

iii) When MP=0 there is no addition to TP.

iv)  When MP is negative, TP starts falling.

I hope you have understood the concept of total product, marginal product and average product