There need not be any secrets in any length of time.
It would depend on the context of what you mean by "secrets." If you are referring to a specific activity or event that takes place over a span of 3 hours and 30 minutes, then it would be impossible to determine the number of secrets without further information.
200 hours = 12 000 minutes
3 h - (3h 18 min) = minus 18 minutes.
Convert one of the hours into 60 minutes and add to the minutes. Thus, 3h 15m = 2h 75m. Now you can easily subtract.
3h+13 = 7 3h = 7-13 3h = -6 h = -2
-9h-6+12h+40 = 22 3h+34 = 22 3h = 22-34 3h = -12 h = -4
3h 30 minutes
60min/h x 3h = 180min
200 hours = 12 000 minutes
3h 50 minutes
3h 30 mins
simplify both sides of the equation: 1/3h+(-4)(2/3h)+(-4)(-3)=2/3h+-6 ~ distribute that 1/3h+-8/3h+12=2/3h+-6 (1/3h+-8/3h)+(12)=2/3h-6 ~ combine like terms for this -7/3h+12=2/3h-6 -7/3h+12=2/3h-6 subtract 2/3h from both sides: -7/3h+12-_2/3h=_2/3h-6-2/3h -3h+12=6 subtract 12 from both sides: -3h+12-12=-6-12 -3h=-18 divide both sides by -3 -3h/-3=-18/-3 h=6
3 h - (3h 18 min) = minus 18 minutes.
6h 10m - 3h 45m = 2h 25m
Convert one of the hours into 60 minutes and add to the minutes. Thus, 3h 15m = 2h 75m. Now you can easily subtract.
3h+13 = 7 3h = 7-13 3h = -6 h = -2
It takes 3h and 34 Minutes driving at the speed limit.
About 2 hours and 31 minutes by a plane of 550 mph.