Answer:
4.5 hours
Explanation:
.5 spends 1/9
1 spends 2/9
1.5 spends 3/9
2 spends 4/9
2.5 spends 5/9
3 spends 6/9
3.5 spends 7/9
4 spends 8/9
4.5 spends 9/9 or 1 full battery
4.5
3.4m questions
4.4m answers