Answer:
The answer to your question is A = 74 ft³, B = 222 ft³, C = 222ft³
Step-by-step explanation:
Data
Total volume = 518 ft³
Prism A volume = Prism B volume / 3
Prism B volume = Prism C volume
Process
Write an equation in terms of volume of B
Volume A + Volume B + Volume C = 518
Substitution
B/3 + B + B = 518
(B + 3B + 3B)/3 = 518
7B = 3(518)
7B = 1554
B = 1554/7
B = 222
Get the volumes
Volume A = 222/3
= 74
Volume B = 222
Volume C = 222
