In part 2, some of the sums of values in corresponding positions in the 6 groups are equal to each other. Some of the sums are equal to the sums of corresponding groups. Specifically:
\[ \sum\limits_{i=1}^6 P_{i2} = \sum\limits_{j=1}^{10} P_{2j} \]
\[ \sum\limits_{i=1}^6 P_{i4} = \sum\limits_{j=1}^9 P_{4j} \]
and
\[ \sum\limits_{i=1}^6 P_{i3} = \sum\limits_{i=1}^6 P_{i7} \]
\[ \sum\limits_{i=1}^6 P_{i5} = \sum\limits_{i=1}^6 P_{i6} \]
\[ \sum\limits_{i=1}^6 P_{i8} = \sum\limits_{i=1}^6 P_{i10} \]