A girl spent 2/5s of her money on a book and 2/3s of what she had left on a folder. she then had $11 left. How much money did she start with?

She started with exactly 28

Find amount of money before leaving on a folder

money on folder : money before leaving on a folder = 2 : 3

the ratio of money she brought = 3 - 2 = 1

money before leaving on a folder = 3/1 x 11

money before leaving on a folder = $33

Find amount of initial money

money spent : initial money = 2 : 5

the ratio of the left money = 5 - 2 = 3

amount of initial money = 5/3 * 33

amount of initial money = $55