The cooper’s weight as an adult dog will be 90 pounds.

Percentage, which is a relative figure used to denote hundredths of any quantity. One percent (symbolized as 1%) is equal to 100 parts; hence, 100 percent denotes the complete amount, and 200 percent designates double the amount specified.

A typical method for calculating a percentage is the formula shown below:

Calculation for the weight of Cooper as an adult;

Cooper’s present weight is 20 pounds.

He will weigh about 350% as much as his current weight.

Calculate 350% of 20 pounds.

= (350×20)/100

= 70

The increment of the weight of Cooper will be 70 pounds.

Thus, the total weight is 20 + 70 = 90.

Therefore, the weight of Cooper after 350% as an adult would be 90 pounds.

To know more about the percent change, here