A sheet of metal is 2 mm wide 10 cm tall in 15 cm long it was 4 grams
what is the density

The Ans is this

you are given the all the dimensions of the sheet of metal, with which you can calculate the volume.

2mm=0.2cm

V = 0.2*10*15 = 30cm^3

The definition of density is mass per unit volume. D=m/V

so the density, D= 4g/30cm^3 = 0.133g/cm^3

OR

Density = Area (cubic cm) /Mass (grams)

.2 cm x 10 cm x 15 cm = 30 cm^3 (cubic cm)

30/4 = 15/2

15 cm^3 / 4 grams

your answer would be a. 12.5 kg