The diagram shows both daily average temperatures and daily average wind speeds for a city over the past week. Here's a breakdown of the questions based on the image:

(a) How many days on which the average temperatures were above 30°C and the average wind speeds were below 20 km/h last week?

To answer this, we need to check for days when the temperature exceeded 30°C and the wind speed stayed below 20 km/h.

(b) On which day was the city the hottest last week? What was the average wind speed on that day?

This will require identifying the highest temperature from the graph and checking the corresponding wind speed for that day.

(c) Someone claims from the diagram that the daily average temperature decreased when the daily average wind speed increased. Do you agree? Explain your answer.

We will need to analyze the relationship between the temperature and wind speed, looking for any trends that confirm or contradict this claim.

Let me know if you'd like a detailed breakdown of any of these parts! Would you like me to go step-by-step through the analysis?