What mass of a 15.0% (m/m) naoh solution contains 125 g naoh?

The mass of 15.0 % (m/m) NaOH solution that contains 125 g NaOH is 833.33 g

calculation

m/m% = mass of solute / mass of solvent x 100

M/M% = 15.0% into fraction = 15/100

mass of solute (NaOH) = 125 g

let the mass of solvent (NaOH solution) be represented by Y

Therefore 15/100 = 125/Y

by cross multiplication

=15 x Y = 125 x 100

15 y = 12500

divide both side by 15

y = 833.33 g