Part A:
there is 60% of lemon juice in a 1 liter of water
so 60% OF the 1 liter
( of technically means in mathematics)
so
60% 1 liter
or 0.6 1 liter
Now to find the total number of liters of lemon juice and water in the bottle
(0.61)+x= 1
(x being the amount of water)
Part B: We can calculate the number of liters of lemon juice that are present in the bottle
60% 1
0.6 1
that is 0.6
So there is 0.6 liters of lemon juice in the bottle
Hope this helps :)