If the question shows two different charts, we can summarise each one separately. After the introduction, we can write a 2-sentence 'overview' of the information, with one sentence to summarise each chart.
Let's try this with the question that you can see here.
Overview / summary paragraph:
Overall, females made up a higher proportion of people living alone than males, and this difference is particularly noticeable in the older age categories. We can also see that the most common number of bedrooms in a single-occupant home was two.