the price of a book is increased from $ 300 to $ 420 . what is the % of increase in its price ?
"explanation : change in the price = rs 420 â € “ rs 300 = rs 120 percentage of increase = change in the price initial price * 100 . percentage increase in price = ( 120 300 ) * 100 = 40 % c"
multiply(divide(subtract(420, 300), 300), const_100)