Answer:
The oldest age of Olivia’s sister can be 11 years.
Step-by-step explanation:
Given: Olivia’s sister’s age is x years.
To write: inequality that can be used to represent the given situation.
As Olivia is 6 years older than her sister,
Olivia's age
As the sum of their ages is no more than 28 years,
So, the oldest age of Olivia’s sister can be 11 years.