Hi

a) Reading off the chart, percentage who had hypertension = 25%

b) We are unable to determine the percentage who had both hypertension and diabetes from the chart.

We only know that the Percentage who had hypertension = 25% and the percentage who had diabetes = 8%. However, not all residents who had diabetes had hypertension, thus it is inconclusive.

c) No, we are unable to conclude. The chart only shows the percentage of residents aged 18-69 years old who had hypertension. We do not have the total population. A higher percentage does not necessarily translate to a higher number of people. 

Hope this helps!

Just to add on, for part (d),

I will agree with the statement that obesity is becoming more serious as it was trending up from 5% in 1992 to almost 11% in 2010.  Even if the actual population size is not given, that fact remains that there is a higher percentage of people who suffers from obsesity in 2010.