Answer:
last Monday is 27
Step-by-step explanation:
perfect square: 4, 9 , 16
2nd Thursday is a day >5 and < 14 day from the begining of the month, therefore the only day fit the criteria is 9th of the month.
last Monday is 27
Sun Mon Tue Wen Thu Fri Sat
9 10 11
12 13 14 15 16 17 18
.........................................................
26 27