If you choose a colour which is much lighter or much darker than the existing colour, you will most probably need 2 coats

Also, with the cutting in, you do one coat all the way around, and you must wait until it dries before you do the second coat.

MOst of the time rollers will distribute much more paint than the brushes, so it is possibly you may need 3 coats of cutting in and 2 coats of roller