Solution

161919

First name
Maisy
School
Long Field Academy
Country
Age
0

Imagine that what is in the lemonade is a fraction. For example:

Beaker A:
Lemonade 10
Water 60

Beaker B:
Lemonade 10
Water 100

Beaker A fraction: 10/60
Beaker B fraction: 10/100

Chnage the fractions so they have the same denominator.

Beaker A:10/60
Beaker B: 6/60

Which ever beaker fraction is bigger is the beaker that has a stronger lemonade.

In this case, it would be Beaker A because 10/60 is bigger than 6/60.