First, see how many parts in total (6+2=8) then divide 80 by 8 which is ten. you then know that each part must be 10 ounces so 2 parts becomes 20 ounces of grape juice and 6 parts becomes 60 ounces of water
The best way to multiply complicated problems mentally* is to break them into chunks.
Start with 20 times 8 to get 160, and then 8 times 5 to get 40. Add these together to get 200. 200 times 3 is 600, and 20 times 200 is 4000. Add these together to get your final answer, 4600.
In other words 8 x 20 + 8 x 5 = 200 200 x 3 + 200 x 20 = 4600
*I assumed you meant mentally, because otherwise you'd just multiply longhand, multiplying two of the three numbers and then multiplying their product with the third.
Answer:
900
Step-by-step explanation:
The figure is a triangular prism
The equation would be V = A * H / 3
V being the volume
A being the area of the pyramids base
H being the height front he base to the top (20)
Base area is 135 (A)
135 * 20 = 2700
2700 divided by 3 = 900
900 is your answer