9 oranges cost £3.15, how much would 7 oranges cost?

7 apples cost 84p, how much would 4 apples cost?

9 sandwiches cost £18, how much would 3 sandwiches cost?

6 footballs cost £30, how much would 3 footballs cost?

7 pears cost £1.60, how much would 14 pears cost?

4 oranges cost 80p, how much do 8 oranges cost?