Which one doesn’t belong and why

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.

Which of the following answers is 5/25 simplified? 1/5 5/5 2/5 1/25

The volume of a cube is 8 in to the 3rd power. how long is each side?