The plus-minus sign represents that there are two possible outcomes.
In this case, we have

. When we branch out the possibilities we got 2 values:

and

Those are the roots of this equation. When they ask their product, they want you to multiply both numbers.
When we multiply them:

When we FOIL the we get:

Simplify:


So the product of the two roots of this equation is 6.
Exp prob (red) = 24 / 60 = 4 / 10 = 2/5
Theoretical prob (red) = (1/2)
Exp prob (blue) = 14 / 60 = 7 / 30
Theoretical prob (blue) = 1/6
Exp prob ( yellow) = 22/ 60 = 11/30
Theoretical prob ( yellow) = 2/6 = 1/3
To find what she saved you need to subtract
500-325= 175
then take 175 divided by the original price (500) to get a percentage so
175÷500=0.35
0.35= 35%
so your answer is she saved 35%