Which of the following would be most likely to have a positive correlation?

1. The population of a town and the number of schools in that town
2. The price of petrol per litre and the number of litres of petrol sold
3. The hours training for a marathon and the time taken to complete the marathon
4. The number of dogs per household and the number of televisions per household

Which of the following relationships would most likely show a negative correlation?

1. The population of a town and the number of hospitals in that town. 
2. The hours spent training for a race and the time taken to complete the race. 
3. The price per litre of petrol and the number of people riding bicycles to work. 
4. The number of pets per household and the number of computers per household.