Final answer:
Two-thirds of the barrels shown need to be painted.
Step-by-step explanation:
To find the number of barrels that will be painted, we need to determine two-thirds of the total number of barrels shown. Since the total number of barrels is not provided in the question, we cannot calculate an exact value. However, if we assume that the total number of barrels is 9, two-thirds of 9 is 6. Therefore, c) 6 barrels will be painted.