100%- 60%= 40%
So, we know water takes up 40% of the volume of Bruce's bottle and that the total volume of water is = 1 L. This means our total bottle volume can be found:
1Liter=

v
1Liter= 0.4v
1/0.4=v
v=2.5 Liters total in Bruce's Bottle
Part A: Equation with one variable to solve for lemon juice volume.
Now that we know the total volume of Bruce's bottle, we can set the percentage of Lemon juice = (to the volume of lemon juice divided by the total volume of the bottle)* 100
Equation:
60=(j/2.5)*100
The variable used in my equation was "j" to represent the volume of lemon juice in Bruce' bottle (in Liters).
Part B: How many Liters of juice are present in the bottle? show your work.
Let's use our equation from part "A" to solve for the value of "j":
60=(j/2.5)*100
first divide each side by 100
60/100=((j/2.5)*100)/100
0.6=j/2.5
Next, to get "j" on it's own multiply both sides of the eq. by 2.5
0.6*2.5=(j/2.5)*2.5
j= 1.5 Liters