Days in a year = 365
clock loses one minute each year, so -365minutes.
An hour is 60 minutes so 365/60 is 6 hours and 5 minutes.
In one year the clock would be 6 hours and 5 minutes too slow.
To find how slow it would be in two years, multiply 365 by 2. (Or multiply 6 hours and 5 minutes by 2)
365 x 2 = 730 minutes
(6:05 x 2 = 12:10.)
in two years, the clock will be 12 hours and 10 minutes too slow.