Which of the following months have 31 days? Classify them as 'yes' or 'no'. January, February, March, April, May, June, July, August, September, October, November and December.


Answer: 'yes', 'no', 'yes', 'no', 'yes', 'no', 'yes', 'yes', 'no', 'yes', 'no', 'yes'.