ANSWER
50%
EXPLANATION
The number was increased from 224 to 336.
To find the percentage increase, we have to find the difference of the two numbers (the increase), divide by the original number (224), then multiply by 100.
That is:
336 - 224 = 112
[tex]\begin{gathered} \Rightarrow\text{ }\frac{112}{224}\cdot\text{ 100} \\ =\text{ 50\%} \end{gathered}[/tex]That is the percentage increase.