Question

What is the percent of increase from 25 to 35?

Answer 1

X - the percent increase

$25+25x=35 \ \ \ |-25 \\ 25x=10 \ \ \ |\div 25 \\ x=\frac{10}{25} \\ \Downarrow \\ x=\frac{10}{25}=\frac{10 \times 4}{25 \times 4}=\frac{40}{100}=40\%$

The answer is C. 40% increase.