Verified answer

Объяснение:

w(NaCl)=m(NaCl)•100%/(m(NaCl)+m(H2O))

w(NaCl)=15×100%/500=3%

w(цукру)=m(цукру)•100%/(m(цукруl)+m(H2O))

w(NaCl)=50×100%/(50+250)=16.7%