#### Answer

80lb

#### Work Step by Step

10 Gallons contain 2lb of Pesticide
First, obtain the amount of pesticides in a single gallon by dividing both values by ten.
1 Gallon will contain $2\div10=0.2 $lb Pesticide
You can now obtain total amount of pesticide powder in 400 Gallons by multiplying both values by 400
400 Gallons will thus contain $0.2\times400=80$lb