This is another great math puzzle to help you improve your logic and critical thinking. The solution shows a step-by-step guide to solve it!
Challenge:
200 percent of a half of \(\frac{1}{5}\) of a tank is full of gas. If 90 gallon of gas is added to the tank, half of it will be filled. What is the capacity of the tank?
A- 150 Gallon
B- 180 Gallon
C- 200 Gallon
D- 260 Gallon
E- 300 Gallon
The Absolute Best Book to challenge your Smart Student!

The correct answer is E.
\(200\%\) of a half of \(\frac{1}{5}\) of a tank equals to \(\frac{1}{5}\) of the tank!
Half of \(\frac{1}{5}\) equals to \(\frac{1}{10}. 200\%\) of \(\frac{1}{10}\) equals to \(\frac{1}{5}\).
90 gallons of gas fills the difference of \(\frac{1}{5}\) and half (\(\frac{1}{2}\)) of the tank. Therefore:
\(\frac{1}{2} T- \frac{1}{5} T= 90 → \frac{3}{10} T = 90 → T = 300\)