How do I add time?

If a person worked 4 1/2 hours on Monday, 4 1/2 hours on Tuesday and 2 hours on Wednesday, does that add up to 12 hours? If not, how much more time would the person need to work the next day to equal 12 hours?

2 answers

add them!!

adding it comes 11 hrs

subtract 11 from 12
okay thx