Hi there!
Using some simple conversions we can determine how many quarts are in 2 & a half gallons.
1 gallon = 4 quarts.
2 gallons = 8 quarts.
Since we're trying to determine how many quarts are in 2 & a half gallons we can separate our problem into how many quarts are in two gallons and how many are in a half a gallon.
2 gallons = 8 quarts.
.5 gallon = 2 quarts.
After adding this together we come up with the answer that there are 10 quarts in 2 & a half gallons. :)
First let's find the factors of each number:
19: 1,19
21: 1,3,7,21
23: 1,23
25: 1,5,25
21 has 4 factors, 25 has 3 and 23 and 19 are both prime numbers (with two factors). 21 has the most factors.
Answer:

Step-by-step explanation:
-3
+ -8
equals;
-3
- 8
Putting it in improper function way:
-
=
= 
in simplified form equals 
Answer:
7230 gallons
Explanation:
The total water pumped out is equal to 210 multiplied by 3 which equals to 630 gallons.
This gives the volume of the tank 3 days ago as 630 + 6600 = 7230 gallons