Răspuns :
X-suma initiala
20% din x= 20/100 * x= 1/5 * x= x/5 -haina
X-x/5= (5x-x)/53 4x/5 -restul
40% din 4x/5= 40/100 * 4x/15= 4/10 * 4x/5 = 2/5 * 4x/5= 8x/25-excursia
4x/5- 8x/25= (20x-8x)/25= 12x/25 -noul rest
12x/25= 216
x=25*216/12
x=25*18
x=450 450/5= 90 -haina
8*450/25= 8*90/5= 8* 18= 144 -excursia