Answer:
Therefore the third container contains
= 43.23 % acid.
Step-by-step explanation:
Given that, One container is filled with the mixture that 25% acid. 55% acid is contain by second container.
Let the volume of first container be x cubic unit.
Since the volume of second container is 55% larger than the first.
Then the volume of the second container is
cubic unit.
cubic unit.
The amount of acid in first container is
cubic unit.
cubic unit.
The amount of acid in second container is
cubic unit.
cubic unit.
Total amount of acid
cubic unit.
cubic unit.
cubic unit.
Total volume of mixture
cubic unit.
cubic unit.
cubic unit.
The amount of acid in the mixture is



Therefore the third container contains
acid.
He will use 33 containers because 9 goes into 296 32.8 times but you cant have .8 of a container so you round it up to 33
85 x 3 = 255
first 2 test grades were 81 and 86:
81 + 86 = 167
Need to find the 3rd to have exact average 85:
255 - 167 = 88
So her 3rd test needs to make 88 to make average of 85
Double check: 81 + 86 + 88 = 255 = 85 + 85 + 85