Answer
After she loses the percent of weight the doctor advised, she will weigh 192 pounds.
Work Step by Step
We can use the following guideline to solve this problem:
Current weight - Amount of weight to be lost = New weight
So, 240 - 20% $\times$ 240 = New weight
So, 240 - .2 $\times$ 240 = New weight
240 - 48 = New weight
192 = New weight
After she loses the percent of weight the doctor advised, she will weigh 192 pounds.