EXPLANATION
As we can see on the statement, the ratio between the blue and the green paint is 3:4
The amount of gallons of paint obtained is 5 gallons.
If we need 3+4=7 drops of paint to obtain 5 gallons, then we can apply the unitary method in order to get the number of gallons of paint obtained for 35 drops as shown as follows:
[tex]\text{?gallons}=35\text{ drops}\cdot\frac{5\text{ gallons}}{7\text{ drops}}[/tex]
Multiplying numbers and simplifying:
[tex]\text{?gallons}=25\text{ gallons}[/tex]
In conclusion, the number of gallons is 25
