We will assume that Anna's income = X
Then Jamie's income = (5/8) x
Let Anna's expenses = y
Then , Jamies expenses = (1/2) y
==> Anna's Income = Anna's expenses + savings
==> x = y + (a/100) *x............(1)
==> Jamie's income = jamie's expenses +savings
==> (5/8)x = (1/2)y + (40%)*(5/8)x
==> (5/8)x = (1/2)y + (1/4)x
Then Anna's saves (1/4) her income = 25%
Let Anna's income be x. And let expenditure by y.
Then since Jamies income is 5/8 of Anna's, Jamies in come = 5x/8.
Jamies expenses are 1/2 of annas.
So Jamiie's expenditure = (1/2)y.
So Jamies savings = income - espenditure = 5x/8-y/2 but this is equal to 40% of Jamie's income = (40/100)(5x/8)
So 5x/8 - y/2 = (2/5)(5x/8) = x/4
Therefore y/2 = 5x/8-x/4 = 3x/8.
Therefore y =3x/8
Therefore the expenditure of Anna's = y = 3x/8.
Therefore savings of Annas = income - expenditure x - 3x/8 = 5x/8.
Therefore the percentage of income Anna saves - ( 5x/8 )100/x = 75%.