Suma totala este a
3/5 a + 15 + 25% x a = a
3/5 a + 15 + 1/4 a = a
12/20 a + 15 + 5/20 a = 20/20 a
17/20 a + 15 = 20/20 a
3/20 a = 15
a = 15 x 20 / 3 = 5 x 20 = 100 lei
In cele doua zile a cheltuit: 3/5 x 100 + 15 = 3 x 20 + 15 = 75 lei
A ramas cu: 100 - 75 = 25 lei