Nick's cell phone was initially empty but was then charged for 45 minutes and has reached a 25% charge. How much longer must the cell phone be charged to reach 100% charge?
The ratio between the time charged and the time to be charged is 100 / 25 = <<100/25=4>>4.
To reach 100%, the cell must be charged for 45 minutes * 4 = <<45*4=180>>180 minutes.
Subtracting the 45 minutes that Jimmy already used to charge the cell phone, there are still 180 - 45 =<<180-45=135>>135 minutes of charging time left.
#### 135