Asked an expert, in fact, the key to this question is to understand the meaning of "inverse ratio", which is inverse ratio. Inverse ratio is defined as the proportional relationship when the product of two variables is constant.

For example, when the value of k is constant, x×y=k, where x is inversely proportional to y.

When the product of two quantities is constant, this relationship is called inverse ratio.

Therefore, from the second item in the question, the latter item is inversely proportional to the former item, indicating that the product of any two items in this series is a constant value.

Since the first term and the second term are 2 and 6 respectively, this fixed value is 12.

You can see that this series is 2, 6, 2, 6. . . Cyclic sequence

The twelfth item is easy to find ~ The cycle period of the series is 2 12/2 = 6.

The twelfth item happens to be the end of the sixth cycle, so the value of the twelfth item is 6.