For the polynomial below, what is the coefficient of the term with the power of
3? x + x +6x+5
A.6
B.1
C.5
D.0

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 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is