Explanation

let the girls' initial pocket money be whole(1) 1/4 of 1 = books, 1/3 of 1 = dress fraction of her money left = 1 -1/4 - 1/3 = 5/12

let the girls' initial pocket money be whole(1) 1/4 of 1 = books, 1/3 of 1 = dress fraction of her money left = 1 -1/4 - 1/3 = 5/12