you would use proportions for it so because percents are always out of 100 it would be 30/100 and part of the stamps are 9 when doing that think of the ratio as part/whole so it would be 9/x there for the equation would be 30/100 =9/x
then you would cross multiply so the new and improved equation is 900= 30x
divide by 30 and you get 30
Kevin has 30 stamps in total
