Class B: 3 and clear. do what the man says.
Class C 3- 152s. That is 3 sm, 100 feet above, 500 feet below 2000 feet horizontal
Class D- 3 - 152.
Class E below 10,000, = 3 - 152s. Above 10K 5SM,1000, 1000, and 1 mile horizontal. or 5 111s
I don't ahve a good one for G. you just have to memorize that the basic clearance is still 3- 152s, which goes less when daytime and more above 10,000:
Day, 1 mile clear of clouds near surface (<1,200 feet above)
Night: 3 152s
Day > 1200 above surface but <10,000 - 1sm and 1- 152
Night 3 152s.
Above 1,200 above ground and >10,000: 5 152s.
These have been burned in for many many years.
Now that you've memorized it, how far away is that cloud over there there?