Answer:
1,200 meters.
Explanation:
Given that the farmer has a field of 300 meters and he wants to fence it with 4 rounded barbed wire, to determine what is the total length of wire he requires, the following calculation must be performed:
300 x 4 = X
1,200 = X
Thus, the farmer needs 1,200 meters of barbed wire to be able to fence his entire field.