What is the greatest common divisor of the three integers 36,45 and 495 ?
Since $36=2^{2} \times 3^{2}$ and $45=3^{2} \times 5$, then the greatest common divisor of 36 and 45 is 9 . Since 9 is also a divisor of 495, then it is the greatest common divisor of the three integers.