If I have for instance 31 days in March which has 8.75 days of NPT this
equals 1.18%, calculated using the following formula.
=IF(Total Days="","",(NPT Hours/(NPT Hours*24))*100) = 1.8%.

What if I only know ther percentage 1.8% and Number of Days in Month 31
days. How do I calculate this to get the number of days NPT?