Answer:
9,11,19
Step-by-step explanation:
let x be the hours and y the percentage
x=0 , y=100
x=8 , y=80
x=9 , y=0
x=10 , y=100 , x=11 still charging so it is still plugged in
x=16 , y=60 and so on ....
x=18 , y=20
and it will charged again
the answer is 9,11,19