Answer:
314 ft cubed
Step-by-step explanation:
To find the volume, find the volume of the cone and add it to the volume of the cylinder.
The volume of a cone is
.
The volume of the cylinder is

Together their volume is 
First you would add all the marbles together because you need to know how many are in the bag in total.
7 + 8 + 5 = 20
Next you simply put the number for blue over the total
8 / 20
And there's your answer.
Answer:
The 5th day must be 90
Step-by-step explanation:
The first 4 days averaged out to 80
You can find their total just by multiplying by 4. That won't tell you the exact values, but it will tell you their total when you add the 4 of them together.
80*4 = 320
Now you need to add another day into the mix. Call it x
320 + x
Now there are 5 days, not 4, and the new total is 82.
(320 + x) / 5 = 82 Multiply both sides by 5
5*(320 + x) / 5 = 82 *5
320 + x = 410 Subtract 320
-320 -320
x = 90