Can you guys explain this step by step? you : )

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.

What is the circumference of a circle with an area of 50.24 cm²?

What is the point of inflection for the function f(x)=2cos4x on the interval (0, pi/2)