mathematics question

Question

An artisan has 63kg of metal of diameter 7000kg/m3.he intends to use it to make a rectangular pipe with external dimension 12cm by 15cm internal dimension 10cm by 12cm.calculate the length of the pipe in meters?

Answer 1

Volume=mass/density
63/7000=0.009m3
0.009*1000000=9000cm3
15*12*L=9000cm3
180L=9000(divide both sides with 180)=50cm
1m=100cm
   ?   =50cm
=0.5m