7.

2

a)

An open rectangular box measuring 28 cm by 20 cm

by 12 cm internally is made of woodcm thick. Find:

the capacity of the box in litres,

the volume of wood used in making the box,

the mass of the box if the density of the wood used is

1.25 g/cm3

b)

c)

J

28 82

1. Capacity of the box in Litres: 7.917L≈8L

2. Volume of wood used in making the box: 1197cm^3

3. The mass of the box: 1496.25g/cm^3

Step-by-step explanation:

1. 29*21*13=7917cm^3

7917cm^3 → 7.917dm^3→7.917L≈8L

2. Outside Volume: 29*21*13=7917cm^3

Inside Volume: 28*20*13=6720cm^3

7917-6720=1197cm^3

3. 1197*1.25=1496.25g/cm^3