The price of a book is increased from $300 to $390. What is the % of increase in its price? Choices.
A) 10 %
B) 20 %
C) 30 %
D) 35 %
E) 45 %

Rationale: "explanation : change in the price = rs 390 – rs 300 = rs 90 percentage of increase = change in the price initial price * 100 . percentage increase in price = ( 90 / 300 ) * 100 = 30 % c"
Answer: C