There are 60 minutes in an hour and 365 days in a year (assuming it isn't leap year0. So the clock loses one minute per day, thus 365 minutes are lost. there are only 60 minutes on the face of a clock. Divide 365 by 60, 6 hrs. and 5 minute.
Thus, the lost time on the face of the clock is 5 minutes.
In 2 years the clock will lose 730 minutes. Just like before you will divide. 730 minutes lost by 60 minutes and have 12 hours and 10 minutes lost. Thus, the lost time on the face of the clock is 10 minutes.
I hope this helps.