Step-by-step explanation:
It is known that density of water is 1.00 g/ml and it is given that volume of the beaker is 55.0 ml.
As density is mass divided by molar mass.
Mathematically, Density =

Therefore, calculate the mass of water present in the beaker as follows.
Density =

1.00 g/ml =

mass =

= 55.0 g
Thus, we can conclude that mass of the water is 55.0 g.