Jawabin nomor 3-4 dong heheh

3.
Konsentrasi larutan(g/L)
=m/V
=20g/125mL
=20g/0,125L
=160 g/L

4.
Massa 3 buah kelereng
=500gram+2ons+50gram
=500gram+200gram+50gram
=750gram

Massa sebuah kelereng
=750gram/3
=250gram

Semoga bisa membantu...