Two tractors worked together and plowed the whole area in 8 hours. If 1 tractor works alone, the field will be plowed within 18 hours. How many hours will it take to plow the field if the second tractor works alone?​

There are a total sales of 2,000 dollars on monday on tuesday sales dropped 10% on wednesday sales dropped another 20% compared with tuesday from wednesday to thursday sales increases by an equal amount to 25% of monday total sales what is the net change in dollars on total sales from monday to tuesday