Answer:
1st pic:
step 2.
2nd pic:
Rene should add, not multiply 2 volumes.
The correct answer is 48+216 =264
3rd pic:
a, for blue prism: V = Area of base x Height = 48 x a =720
=> a = 720/48 = 15
b, for orange prism: V = Area of base x Height = (12xb)/2 x 15 =720
=> b =(720x2)/(15x12)= 8
