Djibo is 17 years old. Five years ago Djibo added his age with his sister's age and the sum was 35. How many years old is Djibo's sister today?
A step-by-step solution is:
28
Age 5 years ago: 17 - 5 = 12.

Sister's age 5 years ago: 35 - 12 = 23.

Sister's age today: 23 + 5 = 28 years.

Djibo's sister is 28 years old today.

.

The answer is 28