Sara, Tina and Luis each have some money. Sara has £65
Tina has £100
Luis has three £5 notes, one £20 note and some £10 notes.

The mean amount of money per person is £80

How many £10 notes does Luis have?

pls help mee​

You can ride your bike around your block 6 times and the whole neighborhood 5 times in 16 minutes. you can ride your bike around your block 3 times and the whole neighborhood 10 times in 23 minutes. how long does it take you to ride around the neighborhood?