Janna spends 1.25 hours of her 8 hour work day answering e-mail messages what percentage of the work day is this time?

To find the percentage, divide the number of hours she answers e-mails by the total number of hours in her work day. This should give you a decimal answer. Once you have the decimal answer, multiply the decimal by 100 to convert it to a percentage.
1.25 / 8 = 0.15625
0.15625 · 100 = 15.625%

Janna spends 15.625% of her work day answers e-mail messages.

Hope this helps. Good luck! :)