algebra

A laptop battery has 81% power after 1 hour of use and 24% after 4 hours use. How long will it be before the battery is completely drained?

 

Your battery is not draining evenly. In the first hour it drained 19%. But, in the next 3 hours it drained 81% - 24% =57% . If we take the average over the last 3 hours we get: 1.57^(1/3) =1.1622 - 1 x 100=16.22%

So:0.0001 =o.1622^n

n =Log(0.0001 / Log(0.1622)

n = ~ 5 hours more to drain completely.

So, it lasted: 4 + 5 = 9 hours.

"Your battery is not draining evenly. In the first hour it drained 19%. But, in the next 3 hours it drained 81% - 24% =57% ." !!!!

 

57% in 3 hours is 19% per hour.