# A man needed $$2\frac{1}{2}$$gallons of driveway topping to weather seal $$\frac {1}{3}$$ of his driveway. How many more gallons will he need to finish weather coating the driveway?

$$5 \text { gallons }$$

Explanation

The reasoning to use here is that the man still needs to complete $$\frac {2}{3}$$of his driveway. Since it took him $$2\frac{1}{2}$$gallons of sealant to complete $$\frac {1}{3}$$ of his driveway, the other $$\frac {2}{3}$$ of it can be covered if he purchases an additional 2 times that amount. To determine the amount of sealant needed, multiply $$2 \times 2\frac{1}{2}$$ gallons. This means that five additional gallons of sealant needed.