Step-by-step explanation:
2.
- the volume of initial prism is 3*3*6=54 cm³;
- the number of cubics of the requested 72 cm³ is 72;
- 'Chelsea wants to add eight layers' means 72=3*3*8 cubics, then one layer in this case consists of 3x3 cubics;
- 'Stephen says they only need to add four layers' means 72=4*3*6 cubics, then one layer in this case consists of 3x6 cubics.
3.
- the volume of initial prism is 4*4*1=16 in³; it means one layer is 16 inches³;
- according to the requirement 3 layers is 16*3=48 in³; three times 16.
- according to the requirement 5 layers is 16*5=80 in³; five times 16.
- according to the requirement 7 layers is 16*7=112 in³; seven times 16.
