my son 12 had a problem for his homework he doesnt get it neither do i can u help

you have to get rid of the mice for the farmer

roll 1 or 2 the small mouse goes

roll 3 or 4 the middle mouse goes

roll 5 or 6 the big mouse goes

mrs farmer rolls the dice she gets 6 the middle mouse goes next she rolls 5 the big mouse goes next she rolls 4 so the middle mouse comes back finally she rolls 2 the small mouse goes and rolls 3 the middle mouse goes again

can you find a rule for the numbers that it takes to get them all out i didnt think there was one

what if there were 2 or 6 mice

help please i have no idea for my son