Need Solution - Xls Download

Hello Friends,
Recently came across a puzzle which involves a family crossing a bridge at night carrying a lamp. Try as I might, I could not figure this out. Could anyone kindly help out with the solution.
Below is the puzzle...
>> It is night, So U must have a fire lamp.
>> Each person cross the bridge at a different speed.
[1-sec] [3-sec] [6-sec] [8-sec] [12-sec]
>> Only 1 or 2 person can pass the bridge at a time.
>> A pair must walk together at the rate of the slower person.
>> The FIRE LAMP is enough for 30-sec only !!!!

Below is the puzzle...
>> It is night, So U must have a fire lamp.
>> Each person cross the bridge at a different speed.
[1-sec] [3-sec] [6-sec] [8-sec] [12-sec]
>> Only 1 or 2 person can pass the bridge at a time.
>> A pair must walk together at the rate of the slower person.
>> The FIRE LAMP is enough for 30-sec only !!!!

Try this
A+B cross in 3 seconds (total time = 3 seconds)
A returns in 1 second (total time = 4 seconds)
D+E cross in 12 seconds (total time = 16 seconds)
B returns in 3 seconds (total time = 19 seconds)
A+C cross in 6 seconds (total time = 25 seconds)
A returns in 1 second (total time = 26 seconds)
A+B cross in 3 seconds (total time = 29 seconds)