Question

If 9.54% of the battery life of each mobile phone is used in a day by a typical user, which mobile phone would use a total of 1.908 hours of battery life in a day?

Answer 1

Sorry, I guess I was in a hurry. This is how I did it after carefully reading the problem. 
9.54% times which mobile phone (the one we are looking for=y) would use 1.908
that is: 0.0954 times y=1.908
0.0954y=1.908 dividing each side by 0.0954, we get y=20
So, the answer is y=20, or the mobile phone is 20