Question

The volume of industrial production increased ten times. What was this increase in percent?

Answer 1

If the production increased the current amount, then is double what the current amount is, and therefore it increased by 100%.  If twice as much, then by 200% and so on.

$\bf \begin{array}{ccll} times&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 1&100\\ 2&200\\ 3&300\\ 4&400\\ 5&500\\ 6&600\\ 7&700\\ 8&800\\ 9&900\\ 10&1000 \end{array}\qquad \qquad \qquad \boxed{1000\%}$