Answer:
D.
Step-by-step explanation:
Set this up as a ratio with #parts of tank on top and #minutes on the bottom and then solve it as a proportion with x being the unknown number of minutes in the second ratio.
[tex]\frac{\frac{5}{9} }{2}=\frac{1}{x}[/tex]
Notice the 1 in the numerator of the second ratio. This is because a whole tank is represented by 9/9 which is the same thing as 1.
Cross multiply to solve for x:
[tex]\frac{5}{9}x=2(1)[/tex]
To solve for x we will multiply both sides by 9/5:
[tex](\frac{9}{5})(\frac{5}{9})x=2(\frac{9}{5})[/tex]
9/5 and 5/9 cancel each other out when multiplied leaving simply "x" on the left. And multiplying on the right:
[tex]x=\frac{18}{5}[/tex]
which divides to 3.6 minutes
