Find the pattern in each line of three numbers. What goes in the blank?

1 2 9

3 4 20

5 6 12

17 12 _

(In reply to

answer by K Sengupta)

The three terms of any of the four subsequences are determined in the following manner.

The first and second terms of each subsequence are equal to the number iof letters when the numbers are spelled out.

For example, 1-> 0ne-> 3; 2-> Two->3. the third term is now obtained by simply multiplying these numbers. So that the 3rd term of the first subsequence is 3*3 = 9

In the fourth and final subsequence, the number of letters in "seventeen" and "twelve" are respectively 9 and 6.

Thus, the third term of this subsequence is obtained by multiplying 9and 6, so that:

The required missing term is 9*6 = 54