prepositions + change

Money isn't the solution ___ every problem.

There has been an increase ___ the amount of traffic on this road.

Everything can be explained. There is a reason ___ everything.

When Paul left home, his attitude ___ his parents was strange.

There has been a sharp rise ___ property prices in the past few years.

What was her reaction ___ the news?

The company rejected the workers' demands ___ a rise ___ pay.

What was the answer ___ question 3?