I need Help, please I really don!t understand.

Which expression calculates the speed in meters per second of an object that travels a distance of 100 m every 20 seconds

How many days was the temperature above 90 degrees?

Mr and mrs smith buy tickets for themselves and their four children. the cost of an adult ticket is ? 6 more than the adult ticket. the total cost of the six tickets is ? 40.50 work out the cost of an adult ticket. in your working let c be the cost of the child ticket and a be the cost of the adult ticket.