Question

For the Rule of 78, for a 12 month period, the last term in the sequence is 12 and the series sums to 78.

For an 18 month period, the last term is______ and the series sum is______ .

For a 24 month period, the last term is_____ and the series sum is______ .

For a 30 month period, the last term is___ and the series sum is ___.