Answer:
Alice's weight is 100 lbs.
Step-by-step explanation:
Let's denote Jane's weight by J, and Alice's weight by A.
The exercise says that Jane is 20 lbs heavier than Alice. So that if you add 20 lbs to Alice's weight, you get Jane's weight. In equation form:
It also mentions that Jane's weight is 120% that of Alice. So that if you multiply Alice's weight by 1.2, you get Jane's weight. In equation form:
Plugging this second equation onto the first equation, we get:
And now solving for A:
Therefore Alice's weight is 100 lbs.
