Mukasa spends 1/4 of her salary on food, 2/5 of the remainder on rent and saves shs.54000. How much is her salary?

Answer 1

her salary --- x
after food she has left 3/4 x
spends 2/5 of that on rent leaving her with (3/5)(3x/4) = (9/20)x
9x/20 = 54000
x = 120000

check
spent on food: (1/4) of 120000 = 30000
leaving her with 90000
spends 2/5 of 90000 or 36000 on rent, leaving
her with 90000-36000 = 54000 for savings